I quit Facebook and Twitter in 2012 out of a combination of bad feelings about where social media was heading as an industry and about its effects on me (i.e., whether I was wasting too much time, oversharing personal info, etc). I quit Costco around the same time because I despise their receipt-checking policy. Quit Dropbox around 2017 in a shift to iCloud. Quit (at least mostly quit) using Google as a search engine around 2018 to support Duck Duck Go and data privacy principles; around the same time I tried switching from gmail to protonmail, but left my gmail account intact and still use it pretty frequently (not out of love for the service, just insufficient motivation to notify old contacts and update old subscriptions.) I quit Microsoft Office last year because I don't like the subscription payment model (now happily using LibreOffice).

For many of the services, I never sought out a real replacement. Instead of named social media, I use pseudonymous accounts on reddit and HN. I stay in contact with family/friends/colleagues using mail and chat. Instead of Costco I go to the local supermarket.

I would love to quit streaming services (Netflix, Disney+) and Amazon Prime but my wife/kids still use them regularly. Also sometimes fantasize about making the leap from the Apple ecosystem to Linux, but am still waiting for some decisive nudge to push me over the edge. Inertia, the sense of captivity and anxiety about learning curves and possible regrets are real factors, but in my experience for most products it is easy to learn the basics and I have never felt any real regret at leaving services I didn't enjoy or feel were compatible with my principles/priorities.