They do have a solid core and likely can be a playoff bubble team. But they are lacking top end talent needed and the depth really isnt great either
And building through free agency really never works either. You have to overpay big time for any impactful player. So cap space is good to have when you have the top end talent and need to build depth, but its less effective when you have some solid players, but need top end talent
Calgary lucked out big time with Gaudreau, and a bit with how good Tkachuk turned out to be. This type of luck is limited and its hard to seem them getting as lucky with the development of 1st round picks.
Losing JG and Tkachuk is like use losing McDavid and Draisaitl (who are a better duo, but in the same tier). We got incredibly lucky to get 97 with a 10.1% chance of winning the lotto, and were very lucky with how Draisaitl turned out.
If lost both of those guys, even if we got back a massive haul for one of them- its unlikely wed ever come close to replacing the impact they brought