How much will the site fall in SEO after the redesign?

Question

Search Engine Optimization

There is a site that occupies 1st place in search engines for its query. I plan to redesign the site, creating it from scratch. How can this affect the position in search engines if:
a) the site structure remains the same, I will copy the content from the old site.
b) change the site structure, change the content as well?

Answer 1

a) if at the same time URLs and Google-page speed remain the same, then nothing will change and everything will depend on the usability of the new design (if users do not like it, there will be failures and this may have a bad effect on positions)
b) this is a risk, everything will depend on the quality of the work done

Answer 2

In the first option, most likely the previous ones will remain or improve.
The second option is unpredictable.

Answer 3

a) if the URLs and tags are the same, everything will be fine;
b) the theme will remain the same? It’s hard to say unequivocally here, but there may be drawdowns and it’s difficult to predict something.

Answer 4

Don't sweat it. You will not be in 1st, but in 2nd place. The clickability is the same.
Most importantly, don't try to be cunning.