It is really about quality of the plugins and not so much the quantity of plugins.

A typical site from me usually includes:

1. A theme functionality mu-plugin (options, post types, meta boxes, etc…), but I really don’t consider that a plugin.

2. Yoast
3. WP Rocket
4. Gravity Forms
5. iThemes Security
6. ManageWP Worker (white labeled).

Ecommerce would include:
7. Woocommerce
8. Shipping plugins such as USPS/FexEx/) whatever is necessary
9. A payment gateway if not using PayPal.

I’ve also used “Members” for user role restriction.

Sliders, custom galleries, cool effects and such don’t get plugins, they get coded into the theme so that I can optimize them better, and have fewer plugins to maintain. I try like hell to keep any custom functionality, such as faq pages, company directories, etc… custom coded and in the mu-plugin as well.

Sent from my Samsung Galaxy smartphone.