We should sell such outdated coins like Tron because such coins will become more and more obsolete over time.
There are many of them which I have no interest to mention any of them. People can just go through the exchanges the old coins are listed and see how disappointing they are now. Many of the new coins now will also become old and not get to all-time high when bitcoin is getting to all-time high. Altcoins are like pump and dump. The ones that are successful now will later not get to all-time high which means if you make money from altcoins, sell them and do not expect their all-time high again or for a long period of time like decades or forever.
This is why altcoins are only good for short term investment because their prices don't seem to prolong its increase, and would all of a sudden dump its value due to some negative market effects, thus they are not suitable for long term hodling.
However, while less potential altcoins are bound to fail, even bitcoin investors as well may also lose their investment if they are not cautious and patient enough, and they don't know how to secure their coins 24/7. Losses are certain in all crypto coins, but if you want to gain profits more often, stick to bitcoin and develop positive attitudes towards your investment.