Some parts such as batteries, storage, ram etc should at least be a standardized.
Manufacturers probably don’t want to standardize on the remaining motherboard/graphics/chassis/cooling because a laptop isn’t like an atx computer where you get modularity at the expense of wasted space. A laptop is basically a 3D puzzle with thermal components. Few consumers would buy a laptop with even a little wasted volume or weight, even if it meant better serviceability and upgradeability. Same with phones. We aren’t going to see modular phones beyond the concept stage either.
I generally agree with your comment. However, when you wrote,
> Same with phones. We aren’t going to see modular phones beyond the concept stage either.
I disagree. I'm writing this on a Fairphone 2, which I bought for its modularity & because running Lineage OS (or any other OS you choose) doesn't void the manufacturer's warranty. While I'm sure Fairphone's sales are small compared to the broader industry, I think they've shown a market exists for ethical, modular phones. I've seen other Fairphones in the wild here in France, as well as seeing them for sale on used goods sites like leboncoin.fr.
Batteries (or rather, individual cells) do have a standard: 18650. Unfortunately too thick for the ultra-thin laptops, but the older Thinkpads use them. I suspect safety is the reason why no one makes replacement laptop battery "empty shells" that take 18650s and have the appropriate balancing/protection circuitry to interface with a laptop, but then again you see mobile phone powerbanks being sold this way... go figure:
There's always beem a trickle of machines like that. The problem is that they're targeted towards industrial usage and RIOTOUSLY expensive.
https://www.bsicomputer.com/products/fieldgo-m9-1760 for example (the first vendor I saw that actually shows prices, as opposed to just request-for-quote)
It starts at nearly $2400 for a low-spec Celeron, and I'm not sure it even has an onboard battery.
What I could see as viable would be a micro-ATX case of similar dimensions, sold as a barebones for like $300-- use the extra volume from not accommodating ATX mainboards to store batteries and charging circuitry, which can be off the shelf because space constraints are minimal. Pop in some reasonably priced desktop components, and you'd have a competent luggable for under $1000.
Manufacturers probably don’t want to standardize on the remaining motherboard/graphics/chassis/cooling because a laptop isn’t like an atx computer where you get modularity at the expense of wasted space. A laptop is basically a 3D puzzle with thermal components. Few consumers would buy a laptop with even a little wasted volume or weight, even if it meant better serviceability and upgradeability. Same with phones. We aren’t going to see modular phones beyond the concept stage either.