It really depends what you are doing. If you control your own idp and you have multiple rp‘s you probably need it tough, but in this case a lot of things are h

It really depends what you are doing. If you control your own idp and you have multiple rp‘s you probably need it tough, but in this case a lot of things are hard, no matter if you use openid connect or nothing. Btw. even if you target entra id or other idp‘s it’s always a good idea to also have a way to trigger the single logout, some people might need it, so it is good to have it behind an Option. Also you should at least implement the backchannel logout. But as said none is really a requirement and often you just use an upfront idp as a second way to login and maintain your own user data in this case single logout is just an addon not a necessity.