Not just RAM and SSD. Displays can break. Power ports can break. USB-C ports can break. Keyboards can break. PCBs can break. And those take time to ship if you have a Dell, HP, Framework or even an Apple machine. I like being able to walk to a nearby store and grab a new MacBook Pro in case I quickly need a new machine to continue my work. My clients typically hire me for short periods and they need me to work at full capacity for that time period. Waiting a week while Framework ships me a new display is not an option.
A Time Machine restore has never failed me. You are fully operational after the backup is restored. Syncing your data onto an SSD via M2 isn't comparable.
Your initial comment made it seem like, the repairable options are just so incovenient to the point where buying a new machine was the solution. So my questions were mainly around why that would be the case. But, it seems like your requirements are pretty stringent to the point nothing other than a Time Machine backup compatible machine would make sense.
OP could make it more generic by removing the Time Machine mandate, and instead using any of a raft of cloud-based backup options. (e.g. I use pCloud, and my approach to a new system is equally quick and pain free.)
Then it just comes down to the time delta between buying a new Mac from a shop in a city (assuming you want one of the immediately-available specifications) versus waiting for Framework parts of be delivered. Framework could optimise this if it was worth their while by having a limited number of common replacement items at fast-shipping fulfilment centres.
However, in reality it sounds less like a genuine question, and more like someone justifying their decision to buy a Mac post-hoc with a range of specific requirements only a Mac could meet.
A Time Machine restore has never failed me. You are fully operational after the backup is restored. Syncing your data onto an SSD via M2 isn't comparable.