It is extremely viable sometimes. One dimensional mons with limited movesets yet powerful moves like Keldeo run two moves of the same type for different power. For in-game however, I would say it wouldn't be necessary due to the little difficulty of in-game battles, and also because the stats aren't set at max 31 IVs all the time for both sides, so you won't know the calcs either to know if it is worth it.
Competitively, it can be a huge advantage. Some mons that only learn a special fighting type move in Focus Blast will sometimes replace it with hidden power fighting. That is literally half the base power and costs a few important IVs, such as speed just so it won't miss and it gets damage off. Just getting damage off to put it in range of the next powerful and accurate attack is one of the ways competitive tries to minimize luck.
But sometimes the extra power is needed for sweeping Pokemon. The base power, compared to other accurate options, can put it in range of OHKOing or 2HKOing. It all matters on what you plan to use that Pokemon for in the end. If it is the main sweeper of the team, yes, I'd risk putting something like Fire Blast or Hydro Pump on something. If not, I'd rather not risk it. But even for sweepers, I feel moves of around 70% accuracy are too risky and unreliable. Its all personal preference. In-game, I would say definitely not. Having more coverage in-game is always more viable in my opinion.
TL;DR There is no right answer in general, its situational. Better for competitve than in-game.
I hope this helps.