People might expect small companies that offer free , as in no fee, services to eventually close those free services or monetise them. But when large companies do the same, it can be a shock to many users. While the news of Google Plus closing is not new, some users may be searching around for alternatives to store many hundreds of photos they uploaded. I suppose the point is that ANY free service may not be forever, even when at the time of signing up that was the lure. On the point of lures, free services can be exactly that. A company might offer a free service, and then when there are enough users, force everyone onto a subscription or add more limitations to the free service, making it less viable. I used a virtual meeting website for a short time to teach students 1:1, which claimed to be free forever, but I guess the new owners didn’t like that idea. That service appears to have gone. If users have become reliant on the service, they may pay for the premium (enterprise) product, while others start their search for another so-called free service.
Things like free web hosting, file sharing, photo storage, etc, may be great for learning and development, but should never be used for more serious, larger projects that would depend on them. Just because a (large) company pushes a free service, don’t expect it to be free or exist forever.