How come my mics never sound clear & natural when plugged in on their own?

Any time I get a new mic and plug it into my laptop it sounds very flat and low quality no matter which mic I use. I ALWAYS have to use an equalizer even when I’m using XLR through my Focusrite Scarlett Solo because it just sounds, not “bad”, but little to no clarity, hence why I use an equalizer. Currently using a Shure MV7 with my preamp, it’s equalized and sounds AMAZING. But I’m just curious to why no matter how many mics I try, I have to tweak them, when I see so many tutorials of different mics and everyone just plugs it in and says “So this is how this mic sounds” and they just plugged it in without changing anything and and it sounds great and don’t know why that doesn’t happen for me. Any feedback is much appreciated 🙏🏻🙏🏻