WordPress is very fast out of the box considering all its capabilities, it's not hard to get in the range of 100ms TTFB out of the box on dirt cheap VPS servers, which is pretty good in my book. The problem is that people add very heavy themes and plugins that push them well above acceptable TTFB numbers.
Full Site Editing with the new Gutenberg editor have amended a lot of that, it's very performant out of the box. Just as an example, I have a site averaging about 200ms for uncached requests, it has an FSE theme and 20 installed plugins, including heavy ones like ACF.
This is all out of the box without cache, but by adding a simple static page cache (either a plugin or something like Fastly, Varnish etc.) you can make it so that the p95 latency drops by 80-90% because most people will see cached page views any way.
Full Site Editing with the new Gutenberg editor have amended a lot of that, it's very performant out of the box. Just as an example, I have a site averaging about 200ms for uncached requests, it has an FSE theme and 20 installed plugins, including heavy ones like ACF.
This is all out of the box without cache, but by adding a simple static page cache (either a plugin or something like Fastly, Varnish etc.) you can make it so that the p95 latency drops by 80-90% because most people will see cached page views any way.