BC and Wrath the gear difference wasn't even remotely as large as it is now.

In BC, you didn't even have any rating requirements except for weapon and shoulders.

In WotLK, you had a system like I'm suggesting where rating requirements were 1600 for hands, 1700 for legs, 1750 for chest, 1900 for head, etc. in season 6 and even lower than that in season 7.

Cata I cannot remember any details but it wasn't much different to BC and WotLK either.

Also, in most seasons back then the previous season's gear could be gotten with honor and wasn't as far behind arena gear as current honor gear is behind arena gear. E.g. in S6 I literally got gladiator (which was 0.5% back then, so way higher than the current gladiator title) with a character that I leveled a month before season end and had only honor items except for the shoulders and weapon which I got the last weeks, playing with a healer who had never gotten gladiator before.