There are some DeFi projects with impossible yield farming and earnings, this percentage are too high to be true, you can never see such on proof of stake coins yet there are many people investing in such DeFi projects, they won't last long and they will surely exit scam
yes, some give as high as 300% of above, it doesn't make sense for a true business that has a long term vision except they are only created for short term purpose, a look at such offer will tell you it is too good to be true, better to join for short term, make profit and get out as soon as possible.
No doubts, such projects are created for long term purposes only, in a short period of time such project can't keep up and the team will have to abandon or exit scam, it's wiser to stay away from too good to be true projects
Honestly for all three of you, the idea of high APY is not really that shocking depending on the price of the token and also why they are capable of doing something like that. First of all they are getting real money from the LP provided and that is what their income is, secondly they just give made up token they created so they are not losing anything, they are not even giving anything the system does that, and lastly those huge high APY is when nobody else invests, which means you make bulk of the profit, whereas if everyone starts to invest suddenly the APY starts to go down.
When you combine all these three you could see why it is possible for these projects to offer 300%+ at times, those are early days of the project that people invest heavily and get free tokens for just "renting" their money without even giving it to anyone or buying anything.