Is there a difference in skill between different blitz categories?

My friend is 1850+ blitz in lichess and I'm around 1550. So about a 300 point different on any given date. That being said, he exclusively plays 3 + 0 and I exclusively play 5 + 3.

When we play together on  https://vidmate.onl/ my time control, I beat him about 40% of the time. I feel like this shouldn't be the case if he's truly 300 points above me.

So my question is this. Do you think there's a difference in skill between the different blitz categories in lichess? Everyone gets lumped into the same blitz category but obviously time is a huge factor in 3 + 0 and not as much with increment, even a small 3 second one in blitz.

What do you guys think?

Are you 1550 on lichess or chess.com?