Because later on that big ecosystem will start to get smaller in most instances. So as much as possible they need to get that big audience for a good start. And hoping that they will keep their support to the project in long-term basis. And yes, marketplace would only be alive if there are a lot of consumers using such platform.
The decrease in the number of users is due to the underdevelopment of the project and the declared service and the toxicity of the community bounty hunters and airdroppers. As soon as a convenient and popular product is created, the number of users will organically grow. So far, many crypto startups do not have this.
EDC Blockchain has a lot of users. Now they release a mobile version of the wallet. Thanks this the wallet will become even more popular and it will be more users.