'Declining' as in getting worse, as in 'not as good as when AC first launched', the inference being that CSP has made AI worse?
Opponent AI was never one of AC's strong points, but is it actually getting worse, or does it just seem that way because other more recent sims have improved things over the past 12 years?
I see lots of vague complaints here and elsewhere about generically 'bad AI', but what specifically are the main issues?
If an actionable report is to be made then clearly defined details will be needed, not only about what actually happens to what cars and on which parts of what tracks, but also what AI strength, aggression etc are being used, and whether any AI apps (or any apps that might indirectly affect AI) are active, what weather is in play etc etc etc.
I don't know, maybe hardware even plays a part if a particularly weak CPU is being used.
Ilja always needs as much detail as possible so that he can try to replicate the same circumstances at his end to better understand what's going on.
It's also always better to use vanilla unmodded Kunos content (cars and tracks) for testing, and disabling all homebrew apps. Mods in any form might actually be causing (or at least contributing to) the perceived problem.