The biggest difference is that you would say “J’ai été accueilli” in a conversation but you would never say “Je fus accueilli” except in a (posh) book.

I think there is a slight difference in meaning or emphasis.

• “Je fus” seems to me like “I am now, with my attention remaining now in the present, talking about a past and finished (accomplished) event”.

• “J’ai été” seems to me like “I personally was then, in the past” and “reminiscing (or developing a story) I still see in my mind’s eye as if it were yesterday”.

I think my answer here agrees with this one.

• I say “accomplished”, and it says s’est produite dans un temps défini et n’a pas de conséquence dans le présent.
• I say “reminiscing as if it were yesterday”, and it says généralement récent, et peut avoir des conséquences

If you’re willing to read an essay about “English language” I might characterize them as Father tongue (impersonal history, formal) and Mother tongue (personal story, oral) as told here: Ursula K. Le Guin
Bryn Mawr Commencement Address