I think 75G is a good size tank without getting too big. I also don't agree that bigger tanks are necessarily easier to keep. I know there's benefits and your water parameters aren't as sensitive with greater water volume, but there are considerations like making sure your filtration can keep up with larger volume (as you'll likely have more/bigger fish), although not a deal breaker more funds spent on equipment and chemicals to sustain the larger water volume, more time to clean and WC, etc.
Hence 75G is a sweet spot especially for someone starting out. Of course, this is a general statement, but it also depends on the individual and what their level of commitment and threshold for challenges may be - 'cause things do happen ;-)