Yes, if you want to complete the journey it is necessary, but understand they intentionally made the last chapter aspirational. Not everyone is intended to complete it and very few builds will complete a Pit75 in time.
While we may think seasons are about completing the
Season Journey, Blizzard does not. I think it’s a massive mistake that serves really no one. They at least moved the pet, but they don’t seem to understand the bigger picture. The average player simply has no chance against that final chapter and those with the time to grind meta builds to take on those challenges are quitting early because they’re still mad there is no new endgame activities.