if his employees felt like they needed to form a union, then he would have failed as an employer

This is a standard anti-union line. It aims to maintain a union-free status quo. Employees in a non-coop union-free workplace have very little leverage to get more of the profits they generate. The workplace environment might be alright, employees might be paid alright. That doesn’t mean they’re paid fairly for the value they create. When there’s no union, employee pay is set by the labour market, regardless of how much value they create for the employer. If an employee creates 10x what they’re paid and they ask for triple pay, their employer would say there’s another candidate to take their place, that it would be a bit of hassle to train so they’d give the employee some marginal raise, to not deal with that. A union on the other hand creates the negotiating leverage to get much more of the value employees create, by threatening a significant financial and reputational loss for the employer. Linua doesn’t want that. Most employers don’t.

https://indiecator.org/2023/08/18/the-problem-with-linus-tech-tips-part-2-a-toxic-work-environment-sexism-assault-and-sexual-harassment/