Exactly. Most deflationary tokens out there have been abandoned by their developers. Only a select few are still being actively traded on the crypto market. It's not about deflation, but rather how useful a cryptocurrency or token is in the mainstream world. But people don't see it that way. They believe that a deflationary token is meant to rise in price for the foreseeable future. This mindset leads to many undesired losses in the long run. Those who know how crypto works, will invest wisely into prominent cryptocurrencies with a proven track record of development and innovation.
As far as choosing a deflationary token as a long term investment, I think that Binance Coin is the best one around. Binance will be periodically burning the supply of BNB, contributing towards the token's price in the long term. Considering that Binance has been widely successful in the crypto space, Binance Coin (BNB) won't be going anywhere. You can see how BNB quickly increased in price since it came into inception some time ago. Buying & holding BNB, alongside deflationary cryptocurrencies like Bitcoin and Litecoin, should give you an ever-lasting investment that will help secure your financial future. As a golden rule, always do your own research regarding any deflationary or non-deflationary token you're willing to invest into. If you do that, you won't have to regret making a bad decision in the long run. Just my opinion