Something for the development of the game
As we already know the game has some big potential, but a major issue is that the skill gap has got to become bigger.
For now it is a matter of some sort of simple decision making mixed with aim skills. The game mechanics and legends abilities do not actually provide the game a lot of options and mostly aim skills are that what sets someone apart from the average players at least for now.
Therefore I see that a good change would be a twist in the game mechanics and legend abilities and characteristics which should be mainly focus on making team work more rewarding and individual skills more appreciated or in other words more valued and on a higher scale.
What you did with Gibraltar and Caustic was a good beginning for balance but can also become a more deciding factor.
The logic here is that their body can take on more damage compared to physically smaller and weaker legends. But wouldn't they have more control over weapons because of their bigger a heavier body and the extra muscles that comes with it as all legends considered to be highly trained?
Giving them more weapon stability with LMGs would make them more advantaged in that category but would still be only a step towards making game changing decisions that would finally increase the skill gap and make competitive more rewarding and encouraged which would give the game a solid future in Esports.
Giving bigger characters more weapons stability and making some characters better with snipers (bloodhound and pathfinder)(as one looks like he was made for it and the second is basically a machine has roles and abilities and characteristics that support being advantaged with snipers), and having robotic legs could help increase movement speed without sprinting and whilst hip firing in addition to a better jumping ability, the lifeline bleeding out slower and healing faster is nothing but compatible with the legend, the wraith having less weapon stability with LMGs only makes sense for the smallest character but should also reward her with making less noise compared to larger legends while moving and maybe higher reload speed for her and the Bangalore in addition to having the Bangalore more adapted to smoke so that she would move a bit smoother and faster and see a bit further, the mirage on the other hand can be a better trickster.
The issue about all of this is that none of this is enough for the skill gap to be on the required level and it would only be more rewarding when specializing with a legend more and adapting to it's play style which doesn't provide the game with the needed skill gap increasing.
Major changes in the game are required for such a thing to happen like when fortnite introduced turbo building and vehicles and players adapted more to the editing.
There has to be a major change that would give each character more things to work with and more contribution for the team and at the same time something in the game mechanics has to change in a way that gives more and more options to work with and makes decision making harder and therefore more rewarding.
One thing I could think of is utilising something that already exist which is the concept of the shield that is generated wether by reviving or an ability. For example there could be something added that allows all legends to access that concept of generated cover that disappears in a bit. I think it could be grenades or deployable robots but it would definitely give fights more difficulty and duration which would make competitive more interesting and make a noticeable change in the skill gap.
These were all thoughts but what actually matter is reaching a bit higher skill gap that is somewhere between where the game is now and where fortnite is as it is too little here and way too much in fortnite. Still I believe the concept of generated shields the disappear is a very good concept to mess around with and limited access to it like on the form of grenades wouldn't be that impacting compared to having deployable drones or robots and the lifeline's passive and gibraltar's ability can be changed or altered depending on how you make the deployable things work but it would definitely enhance the game's potential for the best and it is indeed an idea that would take a lot of work and testing and twisting for it to become reality and even if you start now it could take four to seven months for it to be ready but you already said you are concerned for the longevity of the game and nothing would demonstrate that more so I hope you would actually consider it or it at least focus on increasing the skill gap regardless of the idea to do so wether it is this one or something completely different, as soon as it works it doesn't matter.