DrHappinessOthers have mentioned this, but the key to 'sustain' the esport in EU is not the highest level of play or even the average. Instead its the bottom level of comp play, those that are interested in taking the game more seriously but immediately hit the wall of "How do I start?".
Some areas of improvement that would go a long way to promoting longevity include:
- Encouraging and promoting a welcoming environment for new players
- Guided Games (Think Newbie Mixes, Coaching, etc.)
- Methods of playing regular matches against similar skilled players outside of league play/scrims (newbie & open-only)
- Same as above but a more blended experience (open-mid) not reliant on circlejerks and niche communities
I've held the belief that accessibility is one of the biggest problem areas of the scene since it stops fresh faces joining, and as people leave the community doesnt have others to replace them.
NA needs these (especially the last 2) really fucking bad too. theres like 50 people left in the tf2 community in NA that can actually play in pughub because of the average skill level of the players and how everyone also just only wants to play with their similarly skilled friends