Only if T-blocks and I-blocks come. If there's a drought of T-blocks and I-blocks, then the combo-player wins.
Combo is currently the strongest strategy, under the current Tetris Guidelines.
If you have "too many" I blocks, you run out of Tetris room very quickly (You can only form a Tetris if you've built up 4-rows of 36-minos, with the last 4-square hole being where you use the I-block). If you have "too few" I blocks, you literally can't clear the hole and die.
My overall point is that the bag-randomizer "buffs" Tetris and T-spin players, while "nerfing" combo play. I argue that Tetris-players are the "main strategy", and probably should be buffed to be stronger.
Tetris players also get wrecked by t-spinners as t-spins do double damage compared to how many pieces you clear. The t-spin is the only piece that can send 6 lines back. And with about three bags worth of pieces you can do a t-spin triple + t-spin double + t-spin single = 12 lines.
Only way you can top that is with three all-clears which you most likely won't get.
With the current rules, if you wanna win, you gotta be either t-spinning or comboing in pvp tetris.
You are correct in that TSpins are a great upstacking strategy. Tetris however is a downstacking / defensive strategy.
Consider a "Counter-Tetris": You clear 4-lines of garbage, while dealing 4-damage (+B2B). That's a "effective garbage differential" of 8-lines (+B2B) (you lost 4-garbage, while dealing 4-damage to the opponent). This ideal doesn't always happen, but its far more powerful than a TSpin Triple.
It is impossible to build a TSpin Triple out of garbage, you MUST create a specially crafted overhang. TSpin Triples always leave an overhang. As such, TSpin Triples and TSpin Doubles can at best, clear 1-line of garbage. (and a TST will block your garbage hole until the TST is executed AND the overhang is somehow cleared).
TST into 1-line of garbage is 7 "garbage differential" (2-lines of upstack, 1-garbage cleared + 6 damage sent + B2B). TSD into 1-line of garbage is 5 garbage differential (+B2B) (1-line of upstack, 1-garbage cleared + 4 damage sent + B2B).
Counter-Tetris is 4-garbage lines cleared, 4-damage sent+B2B (8-garbage differential). 3-garbage lines cleared is 7-differential, and 2-garbage lines cleared is 6-differential.
As such, even a 2-garbage + 2-upstack Tetris is more "garbage differential efficient" than all TSpin Doubles, while a 3-garbage+1-upstack beats a pure-upstack TSpin Triple.
Just don't upstack a Tetris, and you'll do fine. Upstacking for a Tetris is grossly inefficient compared to Upstacking TSD or TST.
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My recommended strategy is: TSD for upstack, Tetris for downstacking. TSD keeps the "hole" open for an emergency Tetris if the opponent starts to spike you (an incoming I OR T block can be executed).
A TST overhang blocks the hole however forcing ordering. (you MUST use a T-block), and the overhang will block the I-block until you clean it up somehow.
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Anyway, I argue that going for Tetris should be a stronger strategy... because "Tetris" is literally the name of the game. The "namesake" strategy is weaker than people expect as it is, weakening it further by using a full-randomizer would probably be a bad idea.