INP measures responsiveness for websites and is
due to replace FID as the responsive metric from March 2024. In preparation for this, Google Search Console has started surfacing the INP values for websites and letting them know when pages are below the "good" threshold for a responsive website.
INP is a tough metric to optimise for, but is surfacing real issues that sites may have previously been unaware of.
Looking at
PageSpeed Insights for your site, you have an INP measure of 254 ms (just outside the "good" threshold of 200ms) on mobile, and 95 ms ("good") on desktop. This shows that in general the site on mobile is just outside the good range and that some users are getting less than ideal experiences.
The TBT (Total Blocking Time) audits of the Diagnoses shows a lot of time is spent in serving the ads on your site. This is a fairly common reason for slow responsiveness on websites. Ads, despite bringing in revenue for a site, can be a lot of processing to serve them and site users trying to use your site can suffer because of this. Particularly on mobile. You can choose to serve less ads on mobile to try to avoid this, but obviously that has business implications. I'm also not familiar enough with Blogger or the templates it uses to know whether this is possible.
Other ways of improving responsiveness are by doing a spring clean of your website and removing anything you don't use (old Tag Manager tags, plugins you tried but not longer use...etc). Again I can't talk specifically to Blogger or the template you're using to know if that is possible.