What is your threat model like ? Who are you intending to guard yourself against ?
Is it an assembled PC or a pre-built ? Pre-builts may come with some form of tracking. OS support also may be a concern on some pre-builts.
Maybe something like Debian 12 testing might be a good Linux option to consider, of course Windows or Mac are not recommended for the privacy conscious amongst us. Debian is not the most user friendly to get installer image of, but it has a fairly straightforward GUI based setup for a fresh install.
In case Windows is a requirement then probably look into the Tron script, helps automate a lot of things you might need as privacy settings (among other actions performed by the script).
Note: These are to be treated as opinions, not advice.
Not quite sure about the On by default aspect; on my non-Google phone running stock android, it keeps asking me to enable RCS.
I keep clicking no because there’s a lot of ads pushed through RCS. This is annoying on top of the usual telemarketing stuff you might get due to phone numbers being sold.