The sea contains dangers much more sinister than "safe if you can reach the bottom". You need to know about rip tides and how they can affect the beach you are at. To put it simple, when high tide ends, the water has to go somewhere and it's out into the ocean. If the bottom acts as a wall, the water will flow out through holes in the barrier. This can create currents so strong that no human can swim against them and if you are caught, you are flushed out. If that happens, you need to try to circle around it and see if you can get in next to it rather than through it. If this is caused by rock formations, they can be fairly predictable. Sand on the other hand moves around and a rip tide might not be at the same location two days in a row.
There are other dangers as well. For instance boats and ships. Apart from the obvious getting hit by reckless tiny boats near the beach, big ships can be an issue as well. A ship creates waves. One at the front where it pushes water to both sides, essentially plowing through the water and one from the rear where the propeller is active. Those two waves can travel for several minutes before hitting a beach where they will be noticed as two waves, which are noteworthy stronger than the other waves. There are actually speed restrictions for ships in place in order to protect beaches from this issue. Once in a while a ship is caught speeding.
When the wind goes towards land, all the water will flow inwards. However it doesn't stack up on the beach, meaning it has to go out again. In some cases it will do this at the bottom, meaning if you stick your legs too deep, they can be caught in a current flowing outwards despite the water visibly flowing inwards.
Does this mean entering the water is reckless? I will compare it to driving a car. There are dangers, but if you know them and know how to avoid them, then it's not a huge issue. If you don't know about the dangers or rules and just do something, it can become unacceptably dangerous. A quick google search tells that in California, 58k were rescued and 60 drowned. It doesn't explicitly say how long it took to make those statistics, but numbers I have seen earlier indicates that it's likely in a single year. Australia had 74 who drowned in 2016 while taking a recreational swim.
If you plan to get into the water, I recommend you do some research on rip tides first.