The VHF world, in any built-up area, is a MESS. Strong signals everywhere, giving LOTs of opportunties for inter-modulation products that appear very early in the analog signal processing, which means they cannot be removed in later digital processing. This is just pretty-normal analog RF stuff.
People tend to think of cheap SDRs as “ready to go for any application at all”. In reality, they are components in an overall RF system design. Just as the CPU chip in your computer is a component in your overall computer system.
It isn’t reasonable (yet, wait a few years) to expect a radio that is tunable over such a wide range to also have low-loss analog filter-banks “up front” that are perfectly tailored to your application. Which means that you end up having to do a bit of RF engineering yourself – think of adding up-front filters as no different than selecting appropriate antennae for an application.
NOW, there ARE SDRs out there that are more application specific, like some of the HF-only SDRs that have switchable filter-banks built-in. But if you try to map the same idea over the entire range of the LimeSDR (or others, like HackRFs, BladeRFs, USRPs, etc), then you end up with a very-large and complex switchable filter bank, much of it likely useless for the applications you have in mind…