Battle Cruisers don’t have a great combat record. British Battle Cruisers suffered a real setback at the hands of the German Fleet at Jutland. The problem was more ammunition and powder handling than it was the ships themselves, but the faults were kept secret. The German “Pocket Battleships” impressed the public and made good subjects for movies, but their performance underwhelming.
Capital ships are vulnerable to aircraft, anti-ship missiles, and submarines, a Battle Cruiser would just be a target.
I believe Adm Sir Jackie Fisher warned against placing battlecruisers in the battle line, which Adm Jellicoe did. The High Seas Fleet battlecruisers were closer to true battleships and did far better in the exchange.
But mostly Jutland was like the Battle of Bull Run in the US Civil War. You were using line ahead tactics and signal flags much like Nelson did at Trafalgar, but the weaponry was largely untested. Jutland was that test.