Top Ten Reasons Why Thrash Metal Isn't the Best Metal Music Sub-Genre

Just because you stopped listening to thrash metal after Thrash started to have its problems doesn't mean there hasn't been new Thrash bands that came out that are good here is a list of good Thrash bands that have came out after the initial Thrash movement:
Crash, Nevermore, Havok, Sylosis, Warbringer, Mahatma, Lost Society, Skeletonswitch, Evile, Machine Head, Toxic Holocaust, Vektor, and I'll stop there

Honestly see no point in this list, I mean you can make a list similar to this for every popular sub-genre and the list would be virtually identical

Then you clearly haven't heard Toxic Holocaust. They are a band formed in 1999 that does Thrash Metal and maybe Black Metal.

Yeah each thrash band seems to have plenty of bad albums
Metallica: Load, Reload, St. Anger (I secretly like it), Lulu (if it counts)
Megadeth: Cryptic Writings, Risk, The World Needs a Hero, Th1rt3en, Super Collider (I like some of these)
Slayer: Diabolus in Musica, Divine Intervention, Repentless
Anthrax: Stomp 442, The Threat is Real, We've Come for You All
Testament: Demonic, The Formation of Damnation, Brotherhood of the Snake (originally I included The Gathering, Low which I now got into)
Overkill: The Killing Kind, Bloodletting, Killbox 13 and more
Exodus: Atrocity Exhibition: Exhibit A, Force of Habit
Flotsam and Jetsam: High, Unnatural Selection

Generally, almost all metal bands that have been around for a longer time have more bad albums, but it seems that by thrash metal, every band is aging badly and consistently lowering quality

Interesting list I understand your reasons and I also am not really much of a fan of thrash metal but still I feel like genre comparison lists usually cause more trouble than they are worth.

This could be true of any band that has been around long enough, doesn't apply just to the thrash sub-genre

Sawtooth metal aka Metallica-llica: Testament, Death Angel, Overkill, Exodus, Heathen, Atrophy, Xentrix
Throatache metal aka Deputy Slayer: Kreator, Tankard, Sodom, Havok, Evildead, Stormtroopers of Death, Vortex
Party thrash aka Spreading the Anthrax style: Municipal Waste, Forbidden, Deliverance
Megadeth in Disguise Sells... but Who's Buying: Flotsam and Jetsam, Exumer, Intruder, Onslaught, Laaz Rockit

(I don't think these bands are ripoffs, just grouping them based on which one they resemble most)

I honestly don't agree, if by influenced you mean sound like the big four then sure I guess they are the expectation but by influence you mean the artists that primarily developed them to the band they are today then I would disagree.
I mean every power Metal band sounds like the equivalent of the Power Metal big four and the same with Symphonic metal

I honestly prefer double bass. It sounds more powerful.

So your saying just because Metallica has become the most popular metal band that thrash metal is considered the best metal sub-genre your logic doesn't make since

Even within the big 4 there is a huge fall in popularity from Metallica to Megadeth to Slayer to Anthrax.

Examples of the opposite:
Metallica - we all know the story
Megadeth - even their thrash albums have a wide range
Testament - compare Over the Wall to Perilous Nation
Death Angel - compare Voracious Souls to Left for Dead
Exodus - compare Piranha to Deathamphetamine
Annihilator - compare A Fun Palace to Schizos (Are Never Alone)

This one is because of the fans of Thrash metal they want their favorite band to sound the same each time and when their favorite band tries to change up their sound they crap all over them

Lots of bands also do have diversity in their music. The best example is Sepultura. Moreover, Metallica tried to diversify their sound, but people got angry about it.

What about blackened thrash metal?