Blender Placeholder Helper
Placeholder Helper addon lets you easily switch between a lowres and highres version of an object, in order to improve viewport performance while animating for example.
All the addon does is turn on/off viewport visibility of the collections you configure.
How to use:
Step 1
Copy the highres model and do any changes you want, for example removing unimportant modifiers and decimating it. Put each model in a seperate collection, and disable render visibility for the placeholder collection:
Step 2
Open the placeholder configuration menu (in the n-panel) and add a new placeholder group, and assign the collections you created:
Step 3
You can pin the Toggle Placeholders menu in order to access it at any time, and then just use the toggles to switch between the lowres placeholder and highres:
Credits
Made using Serpens - https://blendermarket.com/products/serpens