Hi, I had a question on picking ( electric guitar )

Do most ( or any ) guitar players pick each different fret once when playing fast/shredding or do they tremolo pick for solos?

I ask because I've been playing for a few months now and I can pick strings at a decent speed but nowhere near the speed of playing solos/some faster riffs. I'm also slow at changing strings when picking this way, yet ( I haven't played any solos/scales this way yet, just 3 frets going up and down the board ) I am able to tremolo pick at a pretty decent speed. However, I find I end up playing most frets 2 times, sometimes 3.

Is this an actual way to pick for shredding/solos or do I need to stop practising it before I get too used to it?

Thanks in advance