As I've heard so many times: the game isn't called sea of friends.
People are not always going to be playing fairly and that's half of the fun. Thwarting a well planned bambooziling at the outpost is one of favorite things to do. There are multiple posts above mine detailing how to turn in whilst jerks are camping. A good way to "juke" a 4man as a solo is to do "drive by turn-in's". Basically, just circle an outpost untill you can put a little bit of distance between you and them, once u have that distance: set your course going with the wind as straight as possible, grab your chicken and as you pass the outpost try to jump overboard at an angle that the 4man might miss seeing and as your ship looks like it's making a b-line away from them and the outpost they will be forced to deal with this in a split second. Split up and try to catch you before you cash in, continue the chase on the vessel not knowing if you are still on board or not. Cash in, mermaid out, rinse and repeat.
I have turned in solo hauls of 10+chests using this tactic against griefing 4man crews with a 90%+ success rate, and the salt on the mics I hear after fuels me lol.
I'm sorry you had an unpleasant experience with the game (so far), please keep in mind that any online game you will find exploiters, griefers, jerks, etc., And sea of thieves is no exception. Once you get over the skill curve you will see how easy it is to out maneuver/smart a Galion in a sloop.
Practice sailing into crazy tight areas, get your powder keg defence game on point, board ships and take out 4 man crews with you and your trusty blunderbuss, practice Cutlass combat, be a stowaway and wait for the perfect time to reveal yourself (or not) and make away with the loot, befriend other crews and gang up on that pesky Galleon that has been trying to take your treasure for 2 hours, roleplay as whatever type of pirate you can think of, play shanties, drink grog, search shipwrecks.
So many things/shenanigans to do just to let jerks ruin this open world experience for you imo. I really hope you don't cheat yourself out of a great gaming experience just because of a few people in the game stopped you from turning in chickens...........
Hope to see you on the open seas buddy.