well very good that your web keep amazing speed, in my experience when you are about 25 to 30 pluggins is not good idea for so many reasons, actually is very painfull when some plugins are getting conflicts, in thos moment i have about 27 and i will implement some direct by code, 80% of free plugins including to much trash code or ads publicity for premium options,ect,ect.
i am using for Cache WP-Rocket and people is amzing, improve about speed and stats on generals, a big difference with other cache plugins
Again as
@Direct Webstore said what bloats your site depends on many factors.
First: Hosting environment. Are you on Apache, Nginx, Litespeed? Shared hosting or VPS? All of these will have an impact on your site speed.
2nd: conflicting plugins. Yes, adding plugins adds some loading latency. But with well-coded plugins, you can add 30+ plugins and still be under 2 sec. load times with good hosting. Put these 30+ plugins under good VPS hosting like Vultr/ Digital Ocean/ Linode/ Cloudways you will see a clear difference compared to shared hosting.
3rd: keep in mind that an e-commerce site must generally have good quality images so less compressed compared to a simple blog. Loading times are relatively higher for those. So don't spend to much time on this as long as it's loading under 3sec per page.
So, in the end, there is not truth. You will have to spend a lot of time to debug bad plugins yourself and chose what works only for your setup.
For cache Wp Rocket, Wp Super Cache + Autoptimize, Wp fastest cache or W3 cache do wonders on Apache or LEMP (Apache/Nginx) stacks.
For Litespeed/Openlitespeed (which I am using now) Litespeed cache is incredibly fast (full page cache) and 100% free with lots of options like free image compression, minification, etc.... A bargain compared to the competition (Wp Rocket). But it is a real pain in the ass to setup correctly, far too many options, not beginner friendly at all.
Sometimes I just miss easy plugin settings with few options that works instantly (like WP super cache).
So forget about the number of plugins, use only the plugins you need and that are stable on your install. Avoid overlapping between plugin functionalities.
And yes there are many 100% free awesome plugins out there. It's all about quality here not quantity.