What I'm trying to say, if you get a good standard color photo, you can mimic any kind of filter with PS or lightroom or whatever. Once you took it with a filter, that's it. No going back
That's not true at all. It may be true for certain situations, but certainly not for all.
Try taking a sunset or sunrise photo
without a grad-ND filter and let me know how it turns out. Those types of shots can grossly exceed the dynamic range of any digital sensor and even film, and they'll always look far better with grad ND filters. Even with a 2-stop grad ND I still have to do massaging in photoshop with the shadow/highlight filter or in DxO to bring up the pretty much dark foreground. Without the filter, doing the same would be pretty much impossible with a JPG, and probably even beyond RAW.
Another example is a circular polarizer for some landscape or scenic shots, especially mid-day when you have a ton of light bouncing around from every which direction. A CP filter will help a ton and I have no idea how you'd even begin to try to mimic a CP filter in photoshop. Good luck with that. :blushing:
Some filters are pretty pointless on digital, like an 81A warming filter. On digital you can just trim out your white balance to get the same effect, or even adjust it afterwards in post-processing very easily. A UV filter doesn't really do anything besides protect the lens. On B&W film, you did need different colored filters depending on what you were shooting. On digital those are pretty pointless too unless you're going for some special effect. One filter that isn't pointless is a regular neutral density filter. If you're trying to get a nice flowing waterfall shot during the day on a tripod, a 4-stop ND filter is indispensible. I don't think you can photoshop a fast shutter speed waterfall photo into a longer smooth flowing waterfall shot.
If you're talking about stuff like color vs B&W vs sepia, just shoot RAW and then you can keep processing the same sensor data in a lot of different ways. You don't really need a real "photographic" filter for that sort of stuff. Even my Nikon D80 has built-in B&W processing filters. The red or especially the orange one tends to give a much nicer look for portraits than when left alone. I don't shoot like that enough to actually warrant buying a real filter though, which might look better.