Regarding Lamine Yamal, I think Xavi and Barcelona have long-term plans for this palyer and they want to keep Lamine Yamal for a long time, after the performance we saw from Lamine Yamal in season for Barcelona they know a player at this age in a gem in the market. Since Lamine Yamal is not 18 years old yet, they can expect his offer for only three years but his agent and Barcelona agreed to extend his offer for longer until he is 18 years old until 2030.
https://www.forbes.com/sites/tomsanderson/2023/09/10/fc-barcelona-and-lamine-yamal-agree-seven-year-contract-extension-plan-reports/
https://www.forbes.com/sites/tomsanderson/2023/09/10/fc-barcelona-and-lamine-yamal-agree-seven-year-contract-extension-plan-reports/
Lamine Yamal started to shine really early and this is great for his career of course. He has been selected for Spain national team already and he even scored a goal on his debut. What more could he have wanted than this? He will probably continue to be a starting eleven member at Barcelona for a long time.
It depends on keeping his performance level decent of course. This isn't going to be easy for a 16-year-old player though. He is very inexperienced but he can get a lot of experience by finding many chances at this young age in a big team like Barcelona.