How to delete pages correctly so as not to lose SEO traffic?

Question

Search Engine Optimization

Hello.
The catalog site contains two main types of pages:
- category pages;
- product pages.
Previously, one category page displayed a list of 10 links to product pages.
Then we changed the number of products in the list to 30, which caused 2/3 of the category pages to simply disappear.
Example.
The category contains 90 products.
So before there were 9 pages in the category with a list of products:
/category-page-1
/category-page-2
...
/category-page-9
After updating, there are 3 such pages left, and the remaining 6 pages give a 404 error.
The next day after making changes, traffic from Google fell.
I assume that the reason is that the number of non-existent pages has suddenly appeared on the site.
I see the following solutions to the problem.
1. Do nothing, waiting for Google to re-index the site someday and traffic will recover.
2. Instead of 404 errors for non-existent category pages, make a 301 redirect to /category-page-1.
Do you have better ideas?

Answer 1

You had to set up 301 redirects immediately after deletion, and even earlier you had to set up category pagination correctly.
At the moment, it is necessary:
​​1- Instead of 404 errors for non-existent category pages, make a 301 redirect to /category-page-1
2- Correctly set up rel prev next pagination for Google and canonicals, or titles and h1 indicating the page so that there are no duplicates for Yandex

Answer 2

You need to set up a 301 redirect to the main category page. In general, as a general rule, pagination should be disabled for indexing. Each page of the site should respond to a specific request. That is, it would be correct to allow only the main page of the category to be indexed.
Indexing of all others can be disabled by setting a canonical link, or by specifying a rule in the robots.txt file
You also need to make the markup rel="next" and rel="prev".
Google recommendations: https://support.google.com/webmasters/answer/16637...
https://www.google.com/?q=%D0%A1%D0%95%D0%9E%20%D0 ...