I think they are.
I saw artworks on Twitter which don't look good (MS-Paint, no shading or simple airbrush shading) and they don't have many likes. The same thing on Deviantart.
There are artworks on Twitter which are well drawn and don't have many likes, but the posts also don't have any hashtags. So people who don't know the artist can't find the drawings.
I always add hashtags when I post my artworks on Twitter, but something seems to prevent people from liking.
Here are the Twitter links for some of my artworks (There are also here on e621 btw):
Perdita from 101 Dalmatians: https://twitter.com/Charlie43964134/status/1484614162277978116
Here on e621 it has 10 times more likes...
Doom Slayer and Marauder: https://twitter.com/Charlie43964134/status/1479161613529886727
I saw other drawings with the Marauder from Doom Eternal and they all have way more likes than my one. If I draw the Marauder, everyone hates it... (I actually did 3 Marauder drawings)
Susie and Ralsei: https://twitter.com/Charlie43964134/status/1469042214886125572
Deltarune fanart and only 2 likes...? Is it maybe Susie's long tongue that turns people off?
They all took me days to draw, but appearently something seems to turn people off. I'm not complaining, maybe it's good to be less popular... It's just odd: The last months I tried to improve the shading, so that the characters look now less flat and yet I have the same amount or should I say lack of likes.
Well, I think there are also other artists who have the same problem. But my main question and the main topic is: Does the amount of likes a drawing get (no matter which platform) shows how good it in it's art quality is?