are portfolio websites still useful? do you get contacts/offers?
that will largely depend on how you market yourself. most people (at least in the industry I work in -- design) will go from job to job and get hired purely based on their written experience, with just a resume and a very simple pdf portfolio.) other, like myself on the other hand, try to market themselves, for example as consultant or freelancers and in this case having a publicly available portfolio, that you can show to people and that you can drive traffic towards does greatly help with getting offers.
that being said, I personally am not at a point where I get a lot of offers just through my website, I find that LinkedIn is still the no. 1 tool when it comes to networking with potential clients, but I'm continuing to improve and see what others -- that do mainly get clients from just them visiting their portfolio -- are doing differently.