I do notice that compared to main series games now, yeah, since we have so many unique tracks in the modern games. Agree with Megan about noticing the cries too, some are so incredibly similar, like Ditto and Poliwag!
Here's a fun fact about generation one, only 37 Pokemon of the original 151 had unique cries. That's less than half of them.
There's an interesting video on youtube that explains old Pokemon cries in a visualized graph, but I'm not gonna link it.
Come to think of it, though, it took a really long time for cries to even get updated in Pokemon, didn't it?
Also, something else I noticed is that sound effects were also few and far in between in generation I battles, but that's to be expected when game boys can't produced a whole ton of unique sounds.