argon2d is anti-GPU
It is no longer true, there are many miners that allow GPU mining using argon2d. More explanation here:
https://www.reddit.com/r/garlicoin/comments/7wf3m6/argon2d_is_gpu_resistant/dyrir63/?utm_source=reddit&utm_medium=web2x&context=3Currently, the most GPU/ASIC resistant functions are probably yescrypt-based. But in reality, there is no such things like "ASIC-resistance". People are not building ASIC machines for such algorithms, because now it is not profitable yet. But when some altcoins will be worth more, they will be created sooner or later. And the only defense in all such cases is changing an algorithm, but it possibly leads to creating a new coin.
GPU resistance is regularly broken on many algorithms, because it is easier to get some GPU hardware and write some code than create some ASIC device from scratch.
you technically don't know what you talking about, you just did some quick googles and jumped to a false conclusion.
Luck uses argon2id (not argon2d) with heavy parameters that make GPU almost equivalent to CPU. To be detailed, memory cost is 64mb, parallelism cost is 4, time cost is 1. Other argon2 projects can be mined by GPU because they use lightweight parameters, such as memory cost is only 1mb. You can test it for yourself, or ask a real expert about this.
Plus, for mining a block the miners have to do 3 rounds of argon2id. So GPU miner is definitely unrealistic here.