If privacy is important, a custom ROM is highly recommended or rather mandatory. Most brands have locked boot loader which can’t be unlocked immediately without voiding warranty. Some let you to using some bs proprietary software but only after few months. That was the only reason I had to resort to getting a pixel. So look into all the brands available to you and check their policy on custom rooms before looking into the mobile themselves.
People or rather I didn’t buy pixel as its more privacy friendly but its the only one available here that let’s me install another ROM on day 1 without voiding warranty. And grapheneos being one of the best privacy focused ROM only available for pixel and that pretty much every ROM is available on pixel is another reason. I was basically forced into buying a google product as everyone else void warranty on unlocking boot loader or they don’t have much of a custom ROM scene.
If you don’t remove play service and shit without being unable to use payment apps and other shut, it’s not gonna work for majority. Those are worst offenders that have to be removed for privacy.