I've been playing the series from the very beginning, so I will be mindful in my response since your last game was in gen 3. To answer the first question, regardless if you're interested in pokemon or not, the switch is awesome. There are some really great games such as Odyssey, Breath of the Wild, Smash, Animal Crossing, ect. If you can find a red box switch right now, the "newer" model that has an increased battery life, then I would make the investment. Now to answer the second question, I believe that the newest pokemon have introduced some really fun features and is the most appealing game to newcomers, which has turned off a lot of the hardcore vets of the series. One of the biggest draw backs is the inability to use every single pokemon and to transfer your pokemon up to the switch, but since you haven't played since gen 3 isn't a big issue anyways since you would need a DS to do so. Sword and Shield aren't the best pokemon game and they aren't the worst pokemon game, so I would say if you're picking up a switch you should give it a try. At the very least you can have a wave of nostalgia and experience an open world version of the safari zone which has been one of the greatest inclusions they have made.