MBPs haven't had a "hard drive" to solder on in a few years: the "T2" security chip is also the SSD controller, managing the "freestanding" flash chips (which are soldered onto the board). The SSD isn't a separate thing at all.

That, however, does not prevent the flash chips from being removable. Sure you would not be able to access the data, but could replace/upgrade the flash without throwing away the computer when they fail. In fact that exists in a real T2 product: Mac Pro. You won't be able to replace it with off the shelf NVMe though.

There are still a few things left for 2022 models

I think it might be unlikely that we see replaceable flash chips come back as it sounds like the built in ones are insanely fast and likely cheaper as well.

I replaced one of the (honestly I don't know what to call them... gumstick sized ssd?) in a MacBook that had it as a separate component and it was a bad idea. It required an adapter board, some large proportion of available products on the market weren't compatible, and even with one that was there was still occasional strange behavior. Soldering in was the least of the problems.

"blade style drive" -> M.2

I also replaced the SSD in my 15" MacBook Pro 2014, and currently use a 4 TB M.2 drive.

When a replacement battery fried my logic board, I didn't lose my data. It didn't take multiple hours to re-clone from backup; I just used a screwdriver to move the SSD over to my spare laptop (13" Pro 2015).

A computer for me is primarily a data storage and retrieval device. Data loss is an existential risk to it. Data security doesn't bother me as much as it does other people; once the hardware is accessible, all bets are off anyway. I do get some strange behaviour with the new SSD (periodic weekly crash/reboot) but still accept that in order to have the larger capacity (4 TB is much more than the 512 GB when the laptop was new).

I did a similar replacement and it was a great idea! But you had to pick the right adapter, also the 2015 MBP had the least compatibility issues.

Wasn't 2015 still in the days of SATA? I put an SSD in mine and it was trivial. It's not at all what the 2016+ models are like.

- 2010 to ~2013: removable SATA SSD in a stick form-factor.

- ~2013 to 2015: removable PCIe SSD (connector not compatible with off the shelf ones though)

- 2016+: soldered

If you go to the other extreme of the spectrum, to the eMMC-based laptops, they are also soldered to the motherboard.

Which is really a shame (I have one Acer Aspire laptop and I mount /var/log as tmpfs without swap so it doesn't devour the eMMC like the RPis do with SD cards)

To summarize: the MBP no longer has a “hard disk”.

It has flash memory that is coupled with the SoC.

This is to make the memory bottleneck tolerable (considering the cpu and ram move 400GB/s)