FFX’s balance is awful if you go straight from point to point and don’t take some long grinding breaks. You’ll hit exactly the kinds of boss-walls you mention, and yeah, the cutscene placement is simply abusive.

Last couple plays I’ve used zig-zag approach when traveling through random encounter zones, effectively ~doubling distance traveled, and encounters. Stretches those out, but removes most of the separate, dedicated grinding.

(Not defending the game design that makes this necessary, mind you)