Not all mods are like that. Lots of mods are actually very well balanced and fit great alongside vanilla content.
You should try it at some point. I'd reccommend Thorium for a beginner mod, alongside Recipe Browser and Boss Checklist, perhaps Yet Another Boss Health Bar too.
There are a lot of smaller mods that simply feel like Quality of Life improvements, which barely add any content at all, as well, like the aforementioned three after Thorium.
That was literally just shown a few posts above yours. The general consensus appears to be: No.