TLDR: Why so?
IMHO, Here are the advantages in general.
1. FREE as in beer.
2. Performs better than most plugins, most of the time, BETTER THAN PAID plugins.*
3. Enormous list of site-boosting features.
4. Make CHEAP VPS server performs like PRO VPS.
5. No conflict, works very stable in spite of ENORMOUS pro features.**
6. Can get 90+ Google Pagespeed rating even your site has a lot of external assets (which I do not have control optimizing that might reduces performance and score).
6. Once tried, you can forget Apache and even NGINX server.
7. Can work with other CDNs.***
* Tried WPRocket, W3TotalCache, WP Super Cache and some others. All losers. If they claim they are no.1 or better, it’s just a propaganda. I mean it.
** I enabled 90% of all features, have no problems at it, if there is, maybe you need a Wiley’s book for dummies. You know that.
*** LSCache + QUIC.cloud addon + Cloudflares can make a good family (just follow the instructions carefully).
Maybe disadvantage(s)
1. If you’re running a VPS with NGINX installed and running, Openlightspeed + NGINX can’t work AFAIK. Note that NGINX comes with performance tuning, so stick with it.
2. Younger than counterparts (referring to OpenLightSpeed server and not the plugin). Well, there’s a room for improvement on this matter.
3. Needs LSWS Enterprise if you need a solid performance + security + stability.
Thats all.
P.S. Now if you disagree with me or you need some help, you may contact me at admin[at]featuristech[dot]com.