It also heavily depends on _what type of content_ your CMS is serving. Blog posts and static pages? Okay, sure, probably fine to bolt WP on top and be done with it.

But as a CMS to build out landing pages for an ecommerce site with 10s of thousands of SKUs? That's where things fall down. I'm not going to reimport my entire catalog into WooCommerce or something just to show a block of 8 products. Do the products also need to be localized for pricing and language? Plugins/custom glue code. PDP pages? Custom content per product based on various supplier disclosure requirements? Meh, at that point, I need to build so much custom stuff on top of WP that I'd actually be better off owning the entire stack and finding a way to use their block editor as a library within my own system.

I've worked heavily in my career with both WordPress and more custom PHP applications and while they each have their tradeoffs, I would never suggest someone to use WordPress at this stage unless they are just getting started and their data models fits without a ton of customization. However, if you're really just starting out, you'd be likely better off with Squarespace or Shopify until your business outgrows those platforms and you need custom software to take your business to the next level. For some businesses, WordPress might be the right answer as a CMS, but for others, they might be better served by other solutions.

The only people I can confidently recommend WP for at this point are actual bloggers who will just use the WordPress.com free tier, or a news organization looking for a high quality interface to publish long form content. For new businesses, you'll be better served by other platforms until you outgrow them and your business needs become complicated enough to warrant custom software.