The one real downside is that learning to cook well at home spoils eating out - it sets your standards for what constitutes a good meal that much higher. If I'm spending €16 on a plate of pasta, it better be a lot better than I can make myself.
Steak is one where I've had better at a restaurant, but it was a $100/person type of place that work paid for. Mine at home is not quite there, but far above the average steak.
When I eat out now I'm hoping to find some combination of spices I don't use or some new idea to take home.
It's a text book size cookbook. The author experiments different cooking methods and documents, taste tests.
It boiled down to seasoning the steak over night so the salt extracts juices and tenderizes. Getting the temperature just perfect using a thermometer (I have a Ninja Foodi Grill that does it automatically).
The quality and thickness of meat also matters. I get mine at Costco or Sam's Club.
My pasta game is a lot better too. Main thing was to stir as the pasta cooks.
Cooking is 60% having good ingredients, 30% avoiding mistakes, and 10% technique.
Sous vide makes steaks 100% idiot-proof. Takes zero skill to get a perfect steak every time. Kosher salt, pepper, granulated garlic, vacuum seal it, drop it into the circulator for ~2 hours, then use whatever the hottest method of cooking you have available to give a quick sear on each side. I use my gas grill pre-heated to about 800 degrees.
But to really kick it up another level, get yourself a smoker. Doesn't have to be a fancy $2000+ offset, a $600 Traeger or even a $200 electric can give good results. Smoke at 225F until it gets to about 125F internal, then sear like above. If you like it extra smokey, you can smoke at a lower temperature.
Now, the only expensive meals I will go out for are seafood. I haven't quite mastered seafood. Fish can be very delicate and fall apart, and it's hard to get the right color on shrimp without overcooking it and drying it out.
I don't like eating out anymore because it's all either expensive greasy over seasoned food, or extremely expensive tiny portion food that maybe tastes about the same as home cooked.