IMO, saying something is was killed by private equity is almost always misattribution. Thriving companies rarely sell out to corporate vultures (the particular brand of PE that people tend to mean when they say "killed by private equity"). Instead, the company has something fundamentally wrong (sometimes it's the company's fault, sometimes the market has shifted, sometimes there are deeper issues in the economics), and it sells out to someone willing to make a buck driving the business into the ground.

Examples include: Family Dining (Red Lobster, Applebee's, etc) was a dying market segment. Millennials and younger tend to put less value on table service than their parents did, preferring food quality over table service when forced to choose. Fast-Casual took over the entire price segment, so the companies either pivoted (see Chili's takeout expansion), or sold out to PE to decompose.

Local Dentistry is getting bought out by PE because the economic conditions that traditionally granted junior dentists the capital to buy out their retiring seniors' practices have ceased. Now, in order to retire, dentists are forced to sell their practices to PE firms.