Is Max fully replacing HBO Max?

Yes. With the launch of Max, HBO Max has been folded into the new service.

Is the new service worth it?

It’s impossible to review Max.com/providers so early, but the service seems to be a continuation of HBO Max in every way.

The prices are comparable, though you’ll have to shell out a bit more for 4K streaming. Considering the extra content you get with Discovery titles being added, that’s not a bad trade-off. Assuming a user experience similar to HBO Max, this is definitely going to be a contender in the streaming wars.