There are magisk tweaks to help combat this but its a annoying game of cat and mouse. Some apps like chase have particularly annoying root detection to deal with. Also regaring safteynet once google fully enforces hardware attestation passing safteynet with tweaks will be borderline impossible (most tweaks try to spoof older phones that don’t support safteynet hardware attestation).
Widevine
Many streaming services (Netflix, Hulu, Disney, etc) will downgrade your video quality to 480p-540p due to L3 from unlocking the bootloader (a step thats usually required before you can root).
Physical security (potential risk)
Unlocking the bootloader is the first step to allowing for rooting and custom roms. One pro/con is when you unlock the bootloader you are partially at risk to a evil maid attack (some one with physical acess to your phone can compromise it). While difficult to do automatically (and probably very very rare) some one could hypothetically place a malicious bootloader that could steel data. The risk of this is mostly low but does exist.