Without saying too much about my specific background, getting into the cleared space is one of the best things you can do in tech. For years I would see people on various subreddits dedicated to cs careers/coding/software engineering look down on the consulting, government contracting, and defense jobs. Everyone wants to chase the big tech companies. The thing is the consulting, gov contracting, and defense roles often push you towards cleared opportunities.
You don't have to worry about competing against H-1B workers since you have to be a citizen. Then on top of that you have citizens who can't qualify due to their background or even want to attempt to qualify. Once you get it you can even go to the big tech companies since they all have cleared opportunities and they give you a cleared bonus. Age discrimination really isn't a thing in cleared roles either. I regularly see much older engineers gainfully employed where big tech is a more an "up or out" model. Big tech brings in young people, chew them up, spit them out and only retain the top performers through RIF(reduction in force) or by not hitting a new senior title by a certain period.