Star studded means that the Galacticos were assembled by Perez - picking the best known and often paying the highest prices to try and get what were seen as the best players into the same side. That is what Real Madrid did.
Messi - academy developed
Xavi - academy developed
Iniesta - academy developed
Busquets - academy developed
Puyol - academy developed
Dani Alves - bought for £23mil + £7mil in add-ons. In hindsight doesnt look expensive but was a lot of money back in 2008.
Real Madrid (second Galacticos era)
Cristiano Ronaldo – signed in 2009 for €94 million from Manchester United
Gareth Bale – signed in 2013 for €100 million from Tottenham Hotspur
James Rodríguez – signed in 2014 for €76 million from AS Monaco
Kaká – signed in 2009 for €67 million from Milan.
Xabi Alonso – signed in 2009 for €35.5 million from Liverpool
Luka Modrić – signed in 2012 for €32 million from Tottenham Hotspur
Karim Benzema – signed in 2009 for €30 million from Lyon
Toni Kroos – signed in 2014 for €30 million from Bayern Munich
Ángel Di María – signed in 2010 for €25 million from Benfica
Maybe if Ronaldo was a better player than Messi then Real Madrid could've been favourites for the league/UCL? Being favourites doesn't mean much - Real Madrid were not favourites when they won the CL 3 times in a row.
Messi is no doubt a generational talent, who was perhaps fortunate to have been in the Barcelona academy at a similar time when other talented players were AND the fact they had an academy, managers and president who trusted those young players to become greats. That was a huge risk in itself. If Messi had been elsewhere, he would've been bought by a top club very early in his career anyway (see Ronaldo and Mbappe for example).
You make it sound like Ronaldo was a pauper playing for Stoke and ripping it up

he played at Man Utd and Real Madrid - during the period when the two clubs were arguable amongst the biggest in the world.