If you're asking how to get the EntityType when using the DeferredRegister way, you can call VERRUCT.get() and that will get you the EntityType out of the registry object. You can do the same for any other type of registry object.
The only thing to be careful about is to make sure that the entities have actually been registered by the time you call VERRUCT.get(), but if you register your renderer at the right time that won't be a problem. In 1.17.1 you register renderers with the EntityRenderersEvent.RegisterRenderers event, I'm not sure about 1.16.5 but it's probably similar. This event will always fire after entities have been registered, so you can safely call the getter.
You should use deferred registration because it ensures that your entities (or blocks, or whatever else you register) get registered at the right time. If everyone did this, it would allow forge to introduce a lot of useful features, such as reloading/enabling/disabling mods while the game is running. This is impossible to do with static initialisers.
By the way, you can click the <> button while drafting your post and it will let you format your code like this:
RenderingRegistry.registerEntityRenderingHandler(VERRUCT.get(), verructRenderer::new);
LifeAndLive.LOGGER.debug("LIFE AND LIVE - Entity rendered");