Before you add another Seatruck-needs better storage post/comment, read this.

It's 3 things really.
1) The lockers are really underpowered compared to standard storage. But this is compounded by the next two issues.

2) Players got spoiled by the Shelter that Sam gets access to at the beginning of the game, which has this stunning storage facility hitherto nether, seen unto before in the Original Subnautica.
And the players of the original game, blush, "oh unknown worlds, you spoil us. You know we can never have enough storage! oooh you naughty developers, know how to keep us happy don't you" (more blushing)
Then you get to the Sea-truck storage module, and your eye glimmers in cat-like meme manner *I can haz twooos av dem?*

For the first time players of the franchise, this is a massive downgrade from the Shelter's storage locker - the disappointment is palpable

3) For us older players of the original game, it gets worse, we start having flashbacks to our disappointment and chagrin of the original inadequacy of the cyclops inbuilt storage lockers.
The player minds race around stuck in a catatonic loop as history repeats itself, the players fall from their comfortable gaming perches and they drop to the floor into a fetal position, convulsing muttering obscenities to the developers, "Why so small storage built into Alterra vessels".

Choas of the individual craftsman.
So if you want to make a small clay sculpture out of clay by yourself (or any construction), as you know from experience, you can go at it yourself and fail time and time again, and have multiple do-overs until you are happy fulfilling your singular vision of the finished product, as your desired ideal version combined with the real-world limitations force a comprise that you can be content with.

As time goes by the craftsman can knock out a quick and easy rough sculptor which many untrained eyes would say was a fairly good product directly, and can spend time polishing the finer details.

Choas of the individual craftsman in a large scale production
Imagine the same scenario but scaled up. This large-scale clay sculpture is MASSIVE and requires a team of people to sculpt in unison to get the job done.
So they start with a massive lump of clay and everyone just start working away at it.

In an ideal world, Choas development works like this:
You have a team of master-craftspeople who know their own strengths and weakness, who have worked together for many projects, they have multiple overlapping roles, background and experience so they can pair/group work together on the same feature. Because they have multiple-roles, they understand the requirements of their colleagues' section and how that section will dove-tail into their own.
They quickly agree on who is doing what, and where they need to go.
And they just go at it - in total faith - as they function together with a singular sculptor

This is incidentally Valve's cabal method.
Valve's devs just stored a collections "sketches", tech-demos and gameplay designs, mechanics. All the devs helped themselves. The Gravity of ideas and collaboration required between devs to improve them started to pull more devs together forming a cabal around a mini-project, which become a themed "section" of whatever main game might need it. So the art team comes in and paints the game-relevant textures suddenly a map is Counter-Strike, Left 4 Dead, or portal2....oh those were the days.

These cabals sadly created little clubs where new staff felt unwelcomed with old cabal member choosing to work together time and time again, or have adopted a hierarchy where valve claimed they never had one.

So this explains the erratic nature of HL1 and HL2, but it gives the opportunity to add pallet cleansing changes to the player's experience, to keep the players fresh. so after combat, there might be a puzzle, after the puzzle came a story element.
The story was painted on after the fact binding the experience together.

The reality is, with chaos programming is that you get a bunch of developers with varying skill levels some with finely honed unique niche's expertise. And they go game-jamming.
You might get an unusable, ugly disfigured mess from all their unplanned chaotic actions that did not go well with their colleague's equally chaotic unplanned actions as the struggled to be on the same page with one another.

So to avoid that mess we have.

Sculpting by committee.
So the team's actions need to be co-ordinated, yes? so you need to plan in advance how the sculpture needs to look (in advance) and how the team should work together by splitting up the work.
Much like the chaotic-master-craftsmen who worked as one mind now written plan becomes the sculptors one mind and the labourers just got to do the job.

Waterfall method has a workman on each body part, attempting to make the final version from day one and then assembling the final sculpture.

Agile has the dev team focus entirely on a single body part so this update it's a rough version of the torso, next update it's an arm or a leg and then the rough sculpture is assembled as planned in order to create the finished future product.
And then the team goes back, update in varying levels of detail per body part.
With the aim that all parts have equal fine detail and polish at a later date.

the future comes, plan or no plan
But if the requirements for the torsor have changed, because the arms are too heavy, to hang on the shoulders, as the workmen opted to put a sword in the hand as the scene required it but no one spotted it beforehand, then that is an issue, because developers can't see the future of the completed product, regardless of expertise and development methodology (choas, Waterfall, Agile).

This is the failing of the waterfall development with which Agile and Choas tried to circumvent the risk of the unknown future by taking smaller dev-cycles (sprints) with concentrating on minimally viable features in the first pass, so they the could guarantee the product would always work, and let the chaos development occur with larger arcs to fit in the missing features that were not there from day one.