If people are complaining about Anthropic (on an only-vaguely related thread) rather than simply switching to a suitable competitor, then Anthropic clearly has some 'monopoly' power over the specific capabilities the complainer wants from them.

Fable/Opus 4.8 outperform Codex 5.5 for me at the general architecture/refactoring/performance work I’m doing, to the point where it’s not worth using Codex. Codex will often spit out non idiomatic code that overcomplicates things.

Not to argue the point but that statement isn’t logical, look at all the complaints about restaurants. Publicly complaining about something doesn’t require it be a monopoly.