34" is on the tall side, but still within standard range.

https://www.thespruce.com/bathroom-vanity-height-8423497 (but I'd never use a vessel sink mentioned in the article)

Our owners bathroom vanities are at 36". The rest are at 30 or so.

I’m 5’4” and mine is 36”. I like the height and how it looks.

36" high, including counters.

36 is too high for me. I am only 5 ft tall. There are times at hotels where the vanity is 36 inches tall and i have to stand on my tip toes to wash my face over the sink. Even my husband who is 6ft didn't like the height. Ours are 32 and it works great for me.

I installed a 35” vanity (including countertop) when renovating one of my guest bathrooms - I’ve been using it while finishing my master bathroom - and while it seemed a bit ”odd” at first - I now love it. Whenever I use my powder room (still has the old 30” vanity from 1996 - will be ripped out shortly - along with kitchen) - it seems really low!

My master bathroom vanity will have a finished height of probably 36” (I’m doing a thick mitered edge countertop in order to not lose any storage in top drawers of vanity - plus, I like how they look).

I am 5’7” - so, I’m sure that factors into preferred heights (my SO is 6’ - so, I’m doing vanity height + mirror/sconce placements all based upon the average of our heights.

You can go higher than 36" if it works for you. We had no trouble selling our home with 37.5 vanities - had 6 offers. However, if you are going higher, think about all possible uses and who else may be using the space. We took the vanity in our new home to 38" but later realized it wouldn't work well for some guests if they used the primary bedroom/bath.