Ths gives you some idea of the trends. It shows that the number of people playing is about as low as it's ever been. It isn't the total number of players, but is a good representative sample to show the trends.
Elite Dangerous - Steam Charts
An ongoing analysis of Steam's player numbers, seeing what's been played the most.steamcharts.com
Yep, almost dead now.
June 2019 | 3,324.4 |
June 2018 | 3,347.6 |
June 2017 | 3,589.2 |
June 2016 | 3,122.7 |
June 2015 | 4,251.4 |