I am thinking of hunting wild boar in Texas, which I've never done before. All info and videos I see mention the calibers they use and I don't really hear about people using 30-06.
Is that just too high caliber for a boar?
It's not that it would be too big of a cartridge, it's just that it's an old cartridge (introduced in 1906) that's no longer what the Cool Kids™ use.
308, for example, is lighter, cheaper, more accurate and while 308 will drop more that really doesn't matter except for really long range shots and then you would have the 6.5 Creedmore which is more flat shooting than both.
With better powders and more aerodynamic bullets, it's possible to get the same or better performance from cartridges with less recoil, which is something that almost all shooters prefer.
So a 30-06 will still work fine, it's just that most people have moved on to better options.