does lulu still work as a mid laner?

First 2 items then swapping to support build I'd say she is C tier

as a surprise pick with past experience, yes. she doesn't scale as well as other mid laners but she's a monster poke/trade machine in lane and can still chunk squishies with some AP lategame. probably I'd go luden's and morellonomicon/other pen items for her good base damages and then get some more supportive pickups for lategame.

heck you could take a guinsoo's or a lichbane if you're feeling gutsy, she has the cooldowns to proc sheen very often and packs a surprising punch.

I mean, machine gun Lulu is still technically a thing again with the changes to Wits End...

That being said Lulu would need to get fed early and suffer almost no harass to keep up with the more traditional damage dealers. If she is solo in a lane it’s almost a certainty she will be camped by the enemy jungler due to her lack of mobility. If, and it’s a very big if, Lulu can get to her power spike before fifteen minutes then she can proceed to be reckless in lane without much pushback.

It’s how I got a pentakill on Lulu in aram years ago, lol.

She's decent into assassins: more utility than Lissandra for the tradeoff of mobility and damage. She gets relegated to the support role come late game no matter how you build her, since her AP ratios aren't as good as they used to be. Still a worthwhile pick though just because of her safety in lane.