Red dot's have magnification. They are basically a traditional rifle scope with a red dot.
Holographs don't. You can get add on to magnify the EOTech. ACOG uses tritium, but not sure how that works. Most of these you can change the shape/size of the image projected: chevron, dot, circle etc.
When I shopped for my deer rifle's scope, I looked at both. But I couldn't get any info on them, so I went with a traditional rifle scope with BDC (bullet drop compensator). My 7mm mag loads have the same drop as a .22-250.
I think the red dot would give faster target acquisition, and the holographic even better. But 4x and less magnification ain't gonna get it done at 300-400 yards. I don't have 20yo eyes anymore.
With AR carbines, the short scopes with long eye relief are popular. With an HBAR or varmint AR, you see more tradional rifles scopes, albeit some are Tactical version with target turrets and fancier reticles.
I have 2 Burris scopes(1 rifle, 1 pistol) and think they are best bang for buck. Their glass is as good or better than 1k$+ scopes. Their controls leaves something to be desired in the lower priced models.
The Burris on my rifle replaced a Tasco 3-9x that was older than me. It had been adequate when hunting Caribou in Alaska at -35. But I wanted stronger magnification and better glass.
One rule of thumb I here from pros: Put as much into scope as the rifle. But I have only seen this in practice once. Friend has Howa 1500 7mm mag with a nice Leupold. About 500$ each. Don't see too many 1000$ scopes on shooter's Weatherby's or AR rifles.
I'm not putting a 450$ Leupold on my Ruger Blackhawk when a used 4x Burris works, or a Zeiss Diavari on my old rusted/busted Parker Hale.
You can get a lot of scope for 300-450$. But a nice rifle that you can hand down to your grandkids, that isn't a single shot NEF, is 800$+.