Depends on the method, really.
Are you just sitting there classically with a fishing rod?
Are you using a spear?
Bombs?
A trawler with a dragnet?

I’ve have several friends with boats that get their limit most times they go out.

Fishing is very complicated to do right. If you know what you are doing, it’s not luck. Most fishermen are relying on “luck.” Success in fishing means experience, research and some innate ability. For many, high tech equipment can greatly round off that learning curve.

That said, the effects of overfishing are profound in most areas that are popular fishing spots. Our watersheds and oceans are in real trouble. I have been a fisherman most of my life and I can see the effects.

^Agreed. The people “catching,” not fishing, know what they’re doing. Those who catch multiple fish would generally be the smaller population of overall active fishing populations.

The 25 out of 100 thing, is not stupid. It’s just WAY too vague…

If want real data, you’d have to examine types of fisher“people,” types of water (salt or fresh,) fish targeted v what was caught, location, time of year, water temperature, weather, even chemistry of given waterways/bodies of water (like ph, and pollution,) bait used, etc…

If you want to get some simple answers, I recommend DNR. They should have a vague understanding of habitats under their watch.

Worldwide? Hire an AI, to do the research for you. Let me know when you find out…

I would add that “fishing success,” is a very subjective concept. Although I assume you (the op) just wants some type of trying to catch v what actual number are caught.

There are just so many variables though. Skill doesn’t even mean that a fisherman catches lots of fish. Personally. If I catch a single good sized red, flounder, cat, sheepshead, I will wrap it in a towel, and paddle my canoe back home. I often “leave ‘em bittin.” It’s part of being a responsible fisherman.
As evidenced, by at least @Blackwater_Park and I, some fishermen are closely involved with their environment.
It’s not as common as it should be, but people still fish/go out in nature responsibly as possible…

I’ll try and think of some stats of just my caught fish/trip. The number would be like, 3/100. Seems like I suck at fishing. Well. I fish, wherever I explore with my canoe. Even when I’m going from one island to another, or place to place I usually trail a line about 50 yards behind me. Rarely does it get a bite…

I have fished my whole life. Success varies from person to person. The success is in getting out and doing it and not in the catch to me.
This became more evident to me as a fly fisherman. Being there in the the river in nature is my measure of success. I also just catch and release. That mindset changes everything on the measure of success.

@Forever_Free I fly fish with my dad who is advancing in years as frequently as I can. We don’t really care about the catch either. That’s a bonus if it happens.

@Blackwater_Park That is wonderful that you success is just being there with your Dad. (First tear of the day)