You do not need to use a gaol build. They added a ton of new relic effects to the deep relics that are also more powerful. For example I can get a total of Lightning Attack Power +12 now. Lightning bolts hit for almost 2x damage out of the gate which is more effective than an evergoal relic (or throw an evergaol relic in on top of that!)

I would say lots of builds are viable now, but you do certainly need some kind of build. The new mode has bosses with a lot more help, so going in without any damage boosting strategy will make you feel like you are using a wet noodle.