Definitely. They nerfed Kanto heavily in GSC, and it felt very empty and very boring. I do like what they did with it later in HGSS, but I still think it's not really enough. Aside from what they already did in HGSS, this is what they should've done:

-Move around some of the Johto and Kanto pokemon so all Johto Pokemon can be found in Johto and some of the Kanto Pokemon are Kanto exclusive (move Electabuzz, Pikachu, Houndour, Slugma, Sneasel, Chansey, Clefairy, and Misdreavus to Johto and move Farfetch'd, Seel, Staryu, Mankey/Meowth, and Tangela to Kanto).
-Bring back Rt. 23 and put trainers there and in Victory Road.
-Reopen the other Underground Path and have both intersect in the middle so you can go in any direction underneath Saffron City (for instance, you can go from Rt. 5 to Rt. 8).
-Reopen Silph Co.
-Allow exploration of the new mausoleum in Lavender Town as a substitute for Pokemon Tower.
-Expand Mt. Moon (if I were to remake the area nowadays, I'd make the inside a giant crater shaped area kind of like Twist Mountain with access to the outside area on top, but they wouldn't have been able to do that back then).