Yes? Dynamic workflows are incredibly powerful - especially for massive rote migrations. They're also particularly nice when you want to stretch an expensive model like fable and you can have it orchestrate a bunch of sonnet agents or whatever and get decent results without having every token burned be a fable token. For my usage style I find the best thing to be about dynamic workflows to be a sort of context management win. The orchestrator agent, if it was implementing everything, would end up deep into its context window where performance degrades steeply, and if you ran into issues early on the session you'd have to be concerned about whether whatever reasoning traces are in context are poisoning your later outputs, while if you're using subagents once you steer the model whatever is doing implementation is starting from fresh context with a new prompt so you aren't forced to kill and restart your session all the time. The way workflows are implemented - scripting with clearly defined stages also mean that the workflow will terminate eventually instead of running forever.
Now with that said, opensi's ultra mode is absolute trash - they should just have stolen Claude code's implementation - and there are clearly modes like max reasoning where they'll burn double the tokens to get another 10th of a percent performance to win benchmarks, which you should basically never be using. They're not making those versions at the expense of more efficient reasoning levels though and I don't mind that they exist (as long as they don't get made the default mode - openai - fix your ultra mode already).