Well, it's clear the game would have more suspenseful moments for the fans, as well as putting more of a premium on a variety of skilled shotmaking by the players, if the serve weren't so dominant. Of course if someone wanted to fix this, it's not hard to think of proposals such as shrinking the service box or, even more extreme, allowing only one serve. There are reasons, of course, that this is very unlikely to happen. For one thing, the current top players have mastered their craft under the current rules, and I suspect they would hate the idea of any significant change. For another, the current rules work fine for casual players, and it would be inconvenient to have different rules at all levels other than professional (I admit that even as a *very* casual player, I liked the idea that I was on the same-shaped court with the same rules as the pros.)
Something that can be done without a revolt is to tinker with the surface, and in fact Wimbledon did this a few years ago, so a backcourt game is more viable there than it used to be, and returners have more of a chance. I find the improvement in watchability to be generally quite noticeable. Also possible is some restriction on rackets -- I've heard this is politically very difficult because of the sponsors, but golf restricts the clubs, so maybe it's not impossible.
By the way: a very modest rule change that players might not find too jarring would be to make all serves that hit the netcord faults (as in volleyball.) No one aims for the netcord, and it's basically luck when it drops in for a let anyway, so this leaves the game relatively unchanged while decreasing the server's advantage by a smidgen.