Indeed! Some of the older fans complain that today's shooters are not about shooting at all, but evading - most have auto-fire too.The small gaps between the different bullet patterns I found the most difficult. I would be fine with countless of waves with bullets, similar to what you get with the easier bosses in Enter the Gungeon if you have played that. When there are several small gaps with changing patterns, it pushes the micro adjustment skill and I find it very hard to keep the mouse/controller steady enough. I probably need to be waaay more relaxed and play on easy mode for practice or fun for that sake.
Those top-down multidirectional shooters are similar yes. Because they react more to player input and positioning they can get quite insane quickly if you take a couple of bad decisions.
On the other hand the older shooters relied more on shooting and memorizing where enemies appear. I'm talking about ones like R-Type and Gradius, which these days are also quite easily available on PC, in one iteration or another. This isn't ideal either but I guess it's purer regarding the origins of the genre. A slow firing weapon can make for quite a tense game as enemies mount up and you have to decide which to aim at first and whether you'll make it to that powerup that's floating about