You could say those are some of the challenges of modeling to scale, but it is definitely a rule of thumb to model to real world scale. At the start of a project one usually researches the measurements of the objects one is going to model, so everything in the scene makes sense, otherwise you will find yourself struggling with thinking something is off, you can't really put your finger into what it is and it's usually things not matching how they look in relation to one another, because a table is slightly larger than a chair. You don't have to go to an extreme and model a microbe to scale, but everyday life things is definitely a must. On top of that, if you model a chair to the size of a building, all of the numbers in Blender start to make no sense, because you then find yourself have to power a light to thousands and thousands of power units just to light a small room, you need 10,000 of power when usually 10 units of power would do.
For every day objects, buildings, vehicles etc. it can also help to add a model of a human to your scene so you can model beside that as a reference.
There are a few reasons to model to scale. 1. It helps to keep things proportional. No having to scale things to match when you start building a scene. not to mention forgetting to apply scale so it doesn't cause problems with textures and modifiers. 2. No camera mathematics. People often times forget to adjust camera focal length and if you motion blur you have to adjust the F stop to match the scale of your objects. If you use real world scale there is no need to calculate what those settings need to be to get the correct looking render. 3. It's a recommendation not a rule. There are plenty of times you may want to adjust scale. Like for instance if you are doing an animation about ants then you want the ants to be human size roughly. Microchip would depend on what your project needs. If it's just chips in a scene or as a prop then real world would be fine. If it was an explanation video or product visualization then you may want to upscale it.
Thanks for the advice everyone, definitely useful. I did notice some renders I was working on needed nuclear powered lights, I looked and my model was huge, so that makes sense.
Thanks again!
Doing a bit of research on correct dimensions helps a LOT in the long run, especially for something like buildings. If you establish correct dimensions early on it becomes significantly easier to make objects look correct in relationship to their surroundings and each other.
For structures, many parts of the world have fairly consistent building codes. In this case you can search for things like "standard width of hallways in a hotel" or "standard riser height of stairs" or whatever you need. There's loads of information available. For things like furniture I tend to look at Ikea because they list the dimensions of all of their items and that will at least get you in the ballpark for what you want to create. Things like desks, coffee tables, counters, average chair seats, etc all tend to be fairly standard heights.
A great resource for the dimensions of a whole variety of things is https://www.dimensions.com/
That said, there is also the approach where one sort of just wings it. Plop in a model of an average sized human and model things to look proportionally correct to that model. It takes a bit of an eye for scale to do it this way but in situations where scale isn't critical it can work okay.