Among other topics here, I’ll add my 2 cents, if I may
For Google services, there are replacement methods like microG. Haven’t tried that myself due to lack of need, but they look generic. So might be useful to those who can’t find a replacement app/service to GS-demanding ones.
Speaking of which, I learned recently how to connect to eduroam and local internet provider secure enterprise Wi-Fi networks using the .crt files. Works the same as those “setup” apps that lazily load up those Wi-Fi profiles with a click of a button.