Ramos did not seem interested in the large salary offer from Al-Ittihad, he preferred Sevilla as a club at the start of his professional career. Ramos still has the opportunity to play in the top league even though he is 37 years old. Sevilla is also one of the clubs competing in the UCL this season.
Sergio Ramos is known for making records with his attitude and red cards. I could imagine being carded from Saudi Arabia altogether if he play there 
As a free agent, he didn't receive an offer from Inter Miami, a Turkish team was looking for him too and offered €11m a year but he refused. He didn't care also about Al-Ittihad offer of €20m a year and preferred to join Sevilla which only can afford €1m which he accepted. Normally after medical visit he will be a Sevilla defender again after 18 years from his departure there.
Sevilla is currently slumped at the bottom of the standings, they have not been able to get a single point so far. Ramos is expected to be able to bring Sevilla to winning ways, wishing Ramos the best for the rest of his career.
I thought it was definitely going to be better for him if he actually chose to go to the Saudi league because they were offering him a lot of money. But I also respect his decision, he decided to go to his childhood club. Of course, this was definitely an emotional decision taken by Sergio Ramos. I always say that a player should choose money at the end of his career. But at the same time, I don't think we can actually criticize the decision of any player who chose to go to his childhood club towards the end of his career and decided to end his career in that club.