Microsoft creates thousands of tons of ewaste for no reason...
Of course there's a reason, you said it yourself: TPM.
With TPM, Software will be able to cryptographically verify that the OS and Hardware are all unmodified. This'll be an end to piracy and end to unauthorized modifications to your PC ("We've detected that you've installed an Ad Blocker, please remove it before accessing your banking website")
This won't happen overnight, but the forced hardware upgrade is all about control (Microsoft over you) and creating a walled garden to drive profits (like Apple).
You can take a look at Android's attestation and how it prevents running your banking apps on a rooted cellphone as an example of things to come.
Thanks for the comprehensive write-up. It convinced me to migrate back to Firefox.
I was on Firefox (8 years ago), moved to Chrome (I liked the non-admin/transparent update feature and Websites didn't break like they did with ff), then moved to brave (basically chrome + more privacy), and now I'll go back the Firefox (I hope I won't encounter too many non-FF websites)