[question] Is it pointless buying virgin olive oil if you're just gonna heat it?

I think you should be fine, in fact, it's probably preferable to use EVOO over other oils even at higher temperatures.

From this study from 2020:

The team noted that at 120 °C there was a 40 percent decline in the polyphenol content and a 75 percent decline at 170 °C when compared to unheated raw EVOO. The team wrote in conclusion; however, “Cooked EVOO still meets the parameters of the EU’s health claim.” [...] “Despite the decrease in concentration of polyphenols during the cooking process, this oil has a polyphenol level that reaches the declaration of health in accordance to the European regulation, which means it has properties that protect oxidation of LDL cholesterol particles.”

From this study from 2018:

In the Acta Scientific Nutritional Health study, 10 of the most commonly used cooking oils were selected from the supermarket and heated in two different trials. In the first, the oils were heated for about 20 minutes until they reached 464 degrees. In the second trial, the oils were heated in a deep fryer to 356 degrees, the highest temperature recommended for deep-frying foods, for six hours.

In both tests, extra-virgin olive oil displayed the greatest oxidative stability, producing lower levels of polar compounds, trans fats and other byproducts when compared with other oils that had higher smoke points.

I also found this Stove Top Temperature Chart handy to know what temperatures the knob levels translate to.

don't overthink it. Use extra-virgin olive oil if you want to impart the flavor of green olives. Use refined/"light" olive oil if you want a healthy cooking oil that won't make your shit taste like olives. EVOO has a slightly lower smoke point, but if you aren't going higher than 400°F then either oil will work fine.

Its just not very heat tolerant, but if you can keep it below its low smoke point its fine

(I'm going to write with confidence, but I'm not an expert, just grew up around chefs. Please feel free and welcome to fact check me.)

Yeah, EVOO is made by cold-pressing the olives, and regular olive oil by hot pressing. Cold pressing releases less oil and also several tasty compounds that come along for the ride. Hot pressing releases more oil but also other compounds that don't taste as nice, so generally regular olive oil will then be refined, removing most of the compounds that give it flavor. If you compare, you'll find that real EVOO[^1] tastes distinctly olive-y, and regular olive oil has very little flavor at all.

When it comes to cooking, traditional advice is not to cook with EVOO because it's got a low-ish smoke point[^2], whereas regular olive oil (which has been refined) will have a higher smoke point. EVOO's smoke point isn't actually that low, but I generally avoid high temp cooking with it anyway in favor of things like avocado oil (my personal go-to), peanut oil, or vegetable oil which are very tolerant of high temperatures. You absolutely can cook with EVOO though if you only want to keep one kind of oil around the house or something.

To clarify: heating up EVOO and cooking with it is fine as long as you don't smoke it. It won't make it any less extra-virgin or anything: to get those less good-tasting things into your oil, you need to heat up the olives themselves.

So are you wasting money if you do cook with it? Maybe.

Do you want what you're cooking to taste like olive oil? If you do, cook with it! Real[^1] EVOO has a distinct taste that won't go away when heated (unless you smoke it). It's great for making stuff like olive oil cake! If you don't care or don't want that flavor in whatever you're cooking, then yeah it's probably a waste of money. There are many less expensive oils that will work well and have neutral flavors or different flavors that you might prefer, including regular olive oil.

[^1]: All of this is avoiding the issue of regular olive oil being passed off as EVOO when it actually isn't. If you want something interesting to read about this evening, try researching olive oil fraud.

[^2]: In case you don't know, smoke point is the temperature where an oil starts to burn, which tastes bad, isn't very healthy, and will probably set off your smoke alarm.

Yes.

Virgin olive oil should be reserved for salads or to dip bread in.

Not sure, but frying with olive oil is kind of a waste anyway

I air fry and add the oil just before serving. It’s easier to clean up and the oil hasn’t been stressed.