Just new bands from the last few years... you can look up new albums by old bands you like and give them a try. Most of the best bands in the genre are female fronted these days.
I'll give another recommendation for:
Wolf Alice
Alvvays.
To me, they are the clear front runners of new Alt-rock bands. Both of their newest releases are going to be on decade lists, near the top.
Otherwise check out some of these (not in any order):
Sylvan Esso - One of the more unique of the alternative music of the present day. Very original sound that sort of fits its own description.
Slow Pulp - A bit shoegaze, a bit dream pop.
Soccer Mommy - A weird female alt-rock artist who has a sound I'd describe a bit as shoegaze meets Dinosaur Jr without the wall of distortion.
Iceage - Male fronted heavier alt-rock band with a slight post-punk edge.
Ethel Cain - One of the more eclectic artists of the present. Hard to describe. Alt-Rock meets slowcore meets americana meets goth meets indie rock meets ambient. Songs run very long
Juniore - A really fun french language alternative band with an ever so tiny tiny tiny rockabilly sound.
La Femme - Another french language alternative band more in the vein of Mid-era Radiohead (Kid A, Amnesiac), and I'm not exactly sure how to describe them. Unique. Some of their covers are VERY NSFW, so look them up with caution.
The Dø - Sort of unusual indie alt band from France (sings in english).
Blushing - Pretty much straight shoegaze
The Beths - About as straight forward an alternative rock band as it gets in the 2020's.
Wet Leg - Yet another girl band... this one has some very good songs that really don't sound like anything else, but generally speaking fit nicely in that "alt-rock" sound.
Beabadoobee - Has a very 90's alternative female fronted alt-rock band sound, very accessible and poppy at times, but if you like bands like The Breeders, you might enjoy this.
Dum Dum Girls - Has a post-punk/goth/new wave sound, but also very poppy elements
Frankie Rose - Alt-pop with a slight influence from new wave
Hippo Campus - Another rare male fronted band, you seem to like Tame Impala... you should at least check this band out. Feels a bit Tame Impala meets Portugal. The Man meets R&B. Definitely different.
Hinds - Spanish all-female garage rock band. If they weren't from Spain, they'd probably be a big deal. I believe most of their singing is done in English.
Indigo de Souza - Alt-rock... unsurprisingly female. haha. Really great songwriting
Je T'aime - If you're into The Cure's darker music, you will almost certainly enjoy this band. From France with mostly English lyrics. Some covers are NSFW so beware.
Alkaloids - An Ecuadorian alt-rock band with a garage/post-punk sound. Really damn good.
Metz - Heavy as hell, post-hardcore. If you like the heaviest, but more punkish side of alternative music, this is a great band.
Snail Mail - Has a very 90's/early 00's sort of sound. Lazy vocals, straight forward instruments, not a heavy, but just straight forward alt-rock.
St. Vincent - Might be too old... but St. Vincent is one of the more unique offerings around these days.