Separate IP addresses for different languages is not in and of itself something that can improve SEO. Hosting content within the country to which it is targeted can improve SEO. There are a couple reasons for this:
- Googlebot can use hosting location as one signal to determine that a site is meant for an audience in a specific country. You get better rankings in that country (and much worse ranking in the rest of the world) when Google thinks your site is meant just for a single country.
- Hosting close to users is much better for performance. It is often much better to host within the country of your users to make the site faster for them. This can indirectly lead to better search engine rankings because Google rewards sites that users seem to like.
Consolidating your hosting won't necessarily hurt your SEO but you would need to take some precautions. The hardest one would be performance. You certainly shouldn't move your hosting across an ocean. You can use content delivery networks (CDNs) that can cache some resources close to your customers even when the hosting is outside their country.
There are several major signals that Googlebot uses to determine when a site is meant for an audience in a specific country:
- The hreflang meta tags included in the pages that include the country code
- Which country the site is hosted in
- If the site is using a country code top level domain
- A specific setting in Google Search Console that can be used for generic top level domains to tell Google to target them to a specific country
Since you already have the country code top level domain, the hosting within the country shouldn't be a major signal to Google. Just the top level country code domain is usually enough. You should consider adding the hreflang tags as well.
Google has a lot more in depth information in their help center: Managing multi-regional and multilingual sites - Search Console Help
For reference, here is a more in-depth article: WordPress Multilingual - How Important Is Server Location? Geotargeting, SEO and CDNs