Culturally, not really okay. But the culture is shifting. People are experiencing widespread tipping fatigue, and there is a backlash. Most of the customer service workers I know really don’t care if you tip or not, obviously they would prefer if you do, because they get some of the money (maybe not all) but they are also understanding that many people do not, will not, or cannot, and aren’t that judgemental about it, provided you are polite and easy to deal with. If you are needy, obnoxious and demanding, providing a generous tip may or may not absolve you of your sins in the eyes of the customer service workers who had to deal with you, but if you don’t, you absolutely will be judged harshly. Don’t be an asshole to customer service workers and make their lives difficult and this doesn’t have to be something that should ever concern you.

Fields where tipping is still most expected include food delivery, and almost all restaurants with full table service (unless explicitly stated otherwise by the restaurant). It’s not required but also not totally uncommon on occasion for more personalized services where someone is taking personal responsibility for your possessions or your appearance, like hairdressing, porters in hotels, movers, cleaners, valet service, etc.

There is zero shame in refusing to ever tip in retail stores or fast food/takeout or anywhere else really, unless you’ve had a truly outstanding experience for some reason. Even then a compliment to the manager usually goes a lot further than a few percent on a tip prompt.

Places that have traditionally relied on tipping such as waiters and delivery drivers it would be considered uncouth to not tip.

Places that have not traditionally relied on tips such as fast food or take out it is considered perfectly normal to not tip. Anecdotally I have seen stories online that the employees of these traditionally non tipping business often don’t receive the tips anyway, so all the more reason not to do so.