[Custom Sidebars] Help With Sidebar Performance Maximization

Hi! I wonder which is the best way to maximize the performance of elements displayed on the website, specially those fixed on the side bar and if there's a tool here that can do the job with automation and UX personalization.

In sites like these with many different buying options where knowledge seeking is an important factor in the customer journey, I wonder if not having the right widgets, CTA's, and a lot of information on the sides is counterproductive.
https://www.findcourses.co.uk/
https://www.educations.com/

Considering the knowledge factor, it doesn't make sense to establish CTA's buttons driving visitors to advanced stages. Due to the great variety of content offered and the different visitor motivations, the user ends up disregarding what's shown to them in the main page even if these content fulfills a knowledge seeking behavior.

Acknowledging nowadays minimalist approach towards website design, I wonder how others are handling the fact of having to compromise content even if they have tons of information ready to show to visitors. I have never really trusted the "less is more" strategy in these situations.

Thereby I'm considering is the implementation of software that could enhance user experience according to the visitor interaction with the website. I know there are already some applications out there that personalize what's displayed on the website like an in-house google ads. I have searched features and plugins here but I haven't found anything suitable beyond sidebars plug ins.

I thought I could find a proper tool here. Let me know if I'm missing something and what you think about this matter.