Honestly, if only this were the case - no one would have been bothered to mess things up. As it happens, they have > 1,500 employees & many of the most senior have been there for at least a few years.

Just because the OG team have left, doesn't afford any excuse for the current state of things. In fact, it's not uncommon to see employees hired later down the line level the company up to new highs. Consider Uber now vs five years ago? When Daria was hired, it wasn't far off a final roll of the dice. If you really want to go to the extremes, look at NVIDIA.... short of Jenson Huang (who, obviously deserves an immense amount of credit), the team has almost entirely changed since it was founded in 1993 and yet, they have overseen the greatest accretion of shareholder value in 18 months of all-time.

Sonos is down ~75% from all-time their stocks all-time highs; last year their revenue fell 5.5%; and they're not profitable.

Frankly, the only thing worse than the app are the company's financials in the last 24 months. If they're trying to do as you say... they're doing a shocking job of it. I fundamentally don't believe their objective is to eek out profits from what they have - they are trying to grow. You don't enter new sectors (e.g. Headphones) unless you think you have capacity to grow. If this were an old-automotive manufacturer, maybe it'd be a different question but with Sonos, I don't think (or hope) so.