If the blockchain a currency or token is on is only as strong as it's developers,
A currency/token where 40% of the supply is held by the developer is only as 'strong' as these developers are.
But a platform/currency/.. without developers who own such a big stake there is no influence (assuming open source).
If its closed source, it requires
trust.
then what is the best way to really find out how to trust it before investing?
Get as much information as possible. Basic information like who they actually are, their degree, .. .
See how they behave, their statements. How they react to negative criticism.
Especially if the developers are anonymous?
If the developers hold a significant % of all circulating coins and stay anonymous. Then you are out of luck. Trust them or don't.
If the developers do
not hold a significant % of all circulating coins, it doesn't matter whether they are anonymous or not because they don't have any influence.