does the Wp tag in a post block search engines from indexing content?

hi, a quick question but for many years when writing a blog post in wordpress, i have used the <more> tag after the first 2 paragraphs, even though my blog only displays the first few lines by default in the list of blog posts that the public can see.

Can i ask is using this now a waste of time and more importantly, if i do use that, does that mean it will not allow search engines to read the rest of the content in the blog posts if you see what I mean?

thanks in advance for any advice

Alex