If Beto wants a career as an elected politician then he should find a safe congressional district after redistricting and serve in the House for a decade or two until statewide victory is a realistic possibility for him.
First Representative for ten or so years then Governor or Senator for 4 or 6, then VP in 2040?
Possible. He definitely hobbled himself by running for President in 2020, he should have stayed in-state for a while.
Same as Steve Bullock. He ran for President first - it was less convincing when he returned to Montana to run for Senate and that doomed him. If he hadn't run for President he might have been able to beat Daines since he was a popular Governor - or at least it would have been closer.