His pure Saiyan nature also held him back from telling his friends to stop him from allowing threats to pass. You could say he was trapped by his nature until he found his equilibrium.
The main theme of Dragon Ball which is "There's always someone stronger" relates to Goku's decision to stay dead, because he believes that he could potentially attract a stronger villain. This is genius writing that turns what defines Goku's character on its head.
Goku's decision to stay dead corresponds perfectly with the theme of taking responsibility of one's actions and the rewards that come with that was present in Goku's development during the RRA arc. He was rewarded a body in other world so he can train and fight for eternity for saving the earth numerous times. This also marked the growth and development of Goku coming full circle because the scale of the responsibility he took increased - from reviving a single man to defending the planet, with the rewards he received corresponding with his growth - From meeting his grandpa to spending eternity doing the thing he love with his mind at peace. It showed how selfless he's grown to be despite being unable to eliminate his selfish tendencies, as by him focusing entirely on the planet's future without expecting to die like he did, much like how he focused on reviving Bora without expecting to meet Grandpa Gohan. There's a great message there about putting your heart into the work or goodwill more than the expected rewards which corresponds with the themes surrounding Goku's mindset in his training
Goku believed his presence was creating real danger for those he loves hence why he decided to stay dead, which was him finding an equilibrium between his desire to fight vs his desire to protect the earth which he was only able to do by accepting himself like he did in the Saiyan arc. If he continued to celebrate what he is after King Kai told him in the Saiyan arc by being overly proud of the perks being a Saiyan provided, he would've ignored his limitations due to his proudness and ended up thinking he doesn't need to stay dead and can happily defend against any strong threats that shows up. If he continued to loath what he is after Radtiz told him he would've referred to himself only as an earthling and not own up to what he is which would've lead to him not thinking too much on his limitations by ignoring what being a Saiyans means for him, leading to him not thinking the earth is better off without him. Accepting himself like he did was the result of his purity that was strengthened throughout his arc, the purity that is the central point of who he is no matter how much it conflicts with his feelings. His pure desire to fight.

This is an extract from my Goku character analysis. You can read the analysis here:
viewtopic.php?t=33476#:~:text=Goku%20in ... 20promises.