Gaming

You can buy agony infusions which are required for higher tier fractals but they're so cheap in gold no one should spend real world money on it and you'll earn it naturally if you're climbing the fractal ladder normally. A lot of guilds even give away the agony infusions if you are struggling to gain them. I recommend trying fractals at T1 even in LFG, you'll usually find other new players to fractals who are willing and expecting new players to it, but it won't hurt to watch a video if you're nervous

Gw2 really does a good job limiting power so you hit max power quickly that you really are just buying convenience.

This is pretty much only possible because most actual power is account bound and as you can hit near power cap so quickly, you're generally skill/knowledge bound instead of power bound

You can buy fractal infusions with gold for sure, but if you progress through fractals at a normal clip you'll also be able to just make them for yourself. It just expedites things or lets you more efficiently gear other characters, but that's severely overstating how easy it is to get infusions on other characters once you have enough to do t4s and CMs. They aren't dropped by dailies per se, but you DO get them while completing dailies. You can also technically buy infusions in the TP that are stat boosts for gold, but that's literally like. 500 dps out of 40k, at most. it's pretty trivial and stat boost infusions are only really useful for people doing benchmarks

There's a lot you can buy with gold, from runes to legendary weapons. But all of it is either cheap enough to get without a credit card (like the runes) or mostly QoL (like legendaries, which aren't more powerful than ascended).

Gems are the premium currency and what you can turn into gold by way of the black lion trading company. They're almost entirely used for cosmetics or convenience items, because a lot of the stuff in game that you spend gold on that WOULD be a power boost is almost always associated with a resource that cannot be purchased with gold, and usually you get the lions share of the gold you would need by way of working towards whatever those resources are.

Food/potions are available through gold though, getting those with real money isn't p2w so much as it is just a convenience fee you're paying, and it's not even an intelligent one. Running like, one moderately profitable meta event for an hour is enough gold to get the food/util you need for your raid build for the next 2 months. Boosters (like the metabolic primer/utility primer) are only there as additional conveniences, and aren't even economical in the first place -- I only use them if the game gives me some for free by way of twitch prime drops or some such. In WvW your commander generally provides you with food/utility for free if you're in a zerg, and in PvP those boosters literally do not do anything, and the buffs are in fact stripped from you as you load into PvP. I cannot overstate how much nothing you get by actually paying real money for any of these boosts. The only advantage you can pay for is stat boosting infusions, but it's so much money for such a negligible buff (to the point where stat infusions are within the range of normal variance in play for 99% of players) that it's not even worth considering in the first place, Level boosts could be considered paying for an advantage I guess but it's really just a convenience fee in most games nowadays to be honest, it's nor a super dangerous thing to have in imo