Since the Mainnet launch was from 2018, you have many years to know the extent of development in the token. If there is no development or update to the code during these years, it is better not to invest, and tokens that last for more than two years are often of a low price and are pumped randomly. Every few months, but the long-term trend for these tokens is the continuous loss of their value.
Therefore, as general advice, if the token has been around for years and has not been updated, then long-term investment in it is a certain loss.