Anecdote, not data:
The local telco incumbent here had a CEO that got measured on EPS and share price appreciation over multiple years. The evil thing was that there was an exponential reward curve: his payoff went up much faster than the associated EPS. So dividends went up, EPS went and the stock soared. Then he decided to retire, right when the latest set of multi-year KPIs came due. He beat them all by a large margin.
Enter his successor, the former CFO. He started and within a year he had to slash dividends while earnings cratered. Three years later new capital was raised. Stock price went down like a rock, I believe -90%.
What happened? Well, said telco didn't invest in infrastructure, and went all out in cost savings. This allowed the competing cable company to get a lead in internet speeds. Telco should have invested in fiber optics, didn't do nearly enough. Before the years of neglect caught up, the CEO was gone.
Worst part of all was that the ill-conceived incentive package wasn't publicly disclosed (don't ask how I know).
So I'm not leery of buybacks in themselves, but very much so regarding the structure of incentives. Sadly, it's still not common to fully disclose this and do it the smart way.