It's true that they never miss the UCL, in fact every year they always bring in top players, their finances are stable which makes Madrid always the strongest candidate to win the UCL every season, this is what all clubs should set an example to be able to maintain the club's finances so that they can Competing with big clubs, Barcelona should have to follow the example of its rivals in financial matters so that it is stable under any circumstances, it is difficult for Barcelona if financial matters always concern them because the problem lies there, so whatever happens Barcelona still has to compete even with current players. At least Barcelona is always consistent in any league so that they always get a pot of money from sponsorships or player sales.
Continuing to build a strong team every season always gives Madrid more opportunities to win the Champions League and even their domestic trophies. That is the reason why Real Madrid is always a dream destination for many world-class players. Now, Real Madrid has made the Champions League their favorite trophy. I wish some top teams in Europe could be like Real Madrid; it would be a great thing. Barcelona always tries to strengthen their squad every season, but financial issues sometimes prevent them from doing so.If not for these financial problems, I believe Barcelona could strengthen their squad by adding world class players, just as Real Madrid has done against next season.
Apart from financial and management differences, at least differences also occur in regeneration. After all, so far Real Madrid has never really lost any great players in the team, so even though their key players leave or retire, in reality Real Madrid still manages to maintain its performance to remain good and consistent throughout the season. Meanwhile for Barcelona, when key players leave, in reality Barcelona needs time to adjust to the players in their squad.
Although indeed, when only one or two key Barcelona players leave, but in reality there are still other main players who are still available but still, Barcelona finds it difficult to have a good performance even though there are only slight changes in the team. Thus, of course Barcelona is still often left behind by Real Madrid, moreover Real Madrid's trophy haul in the Champions League is really hard to beat.