Is more VRAM better? Yes. But that 5060ti will give you higher frames than the Arc B580 in more use cases. In a perfect world we'd all have 5090s with 32GB of RAM. But we live in a world were people are playing new games on 8 year old hardware with 6GB of VRAM.
I´m one of those lol, playing Ninja Gaiden 2 Sigma, the new remaster of Gears of War and SH 2 Remake on my old GTX 1660 Super!
This is why i´m trying to upgrade, without changing the entire PC, and also all this RAM stuff makes it impossible to upgrade to DDR5 Mobo
It's a good overview, but you still need to look at your local market and compare the advice being given.
I forgot to update the OP, but i went with this one
https://www.amazon.com/dp/B0F9LN5VZ6?ref=ppx_yo2ov_dt_b_fed_asin_title
Amazon still haven´t charged me, hope they make the debit and send the card pretty soon. If the purchase gets cancelled by them, i´d probably aim for a used RTX 4060 TI 16 GB, i saw on my local marketplace (hope doesnt get sell soon) cheaper than the 9060 XT, because the a new RX 9060 XT here in Colombia it´s more expensive than the Amazon´s offer. Finally, the 5060 TI 16 GB here and also on Amazon it´s more expensive than 9060 XT, and also i will have to buy new PSU (mine it´s 500 W, it needs 650 W), while the RX 9060 XT works with the 500 W fine.
But all i gotta say it´s, 8 GB it´s just a viable option if you don´t wanna go more than 1080p and play more eSports stuff than SP experiences. And if you you with 8 GB, make sure it´s on a modern rig PCIe 5.0 and GDDR5.
For an older build like mine, if your budget doesn´t allow for a 9060 XT 16 gb or 4060/5060 ti 16 gb, i´d say go for a RTX 3060 12 GB,