I was born in Simferopol and most of my relatives still live there. Here's a few things I can tell you almost first-hand.
The vast majority of people there are ethnic Russians who don't even speak Ukrainian. Khrushchev's 1954 transfer of Crimea to Ukraine did not mean anything to them until the Soviet Union split up. Since then the Ukrainian government introduced Ukrainian as the official language of the autonomous republic of Crimea, forcing the Russians to learn Ukrainian for anything official. Then they made Ukrainian the mandatory first foreign language in schools and soon the first language spoken; teaching the children's native Russian as a foreign language once a week.
Any foreign investments (like the EU's) went straight into the oligarchs' pockets, leaving health care, infrastructure, etc. in ruins. No running water after 10:00 PM, and even then it's just cold.
Pensioners like my grandmother often continue to work well beyond retirement to supplement their income enough to get by. Most medical equipment in hospitals is still from the Soviet era; clinics are usually out of medical supplies, i.e. if you want treatment you are expected to bring your own antiseptics, bandages, etc. Paying doctors for better treatment is a given.
Putin's invasion was ridiculous, no question. But honestly, that's exactly what many Crimeans were desperately hoping for for a long time. Say what you like about the Russian government, but it's way better than anything Ukraine's ever seen. Remember the fist fights in Kiev's Parliament? A regular show.
Changes coming to Crimea:
Return to the Russian school system in addition to local Ukrainian schools.
25% increase in retirement pay every quarter until it reaches Russian standards (100% increase overall) in addition to widow's pension, which previously has just not been payed at all.
Complete modernization of health infrastructure.
Repair and restoration of public infrastructure and venues including parks and plazas (you should see the current state they're in).
Exploitation of the abundant natural gas reservoirs off shore; there has just not been any funding previously. Crimea is expected to become self-sufficient and maybe even export natural gas at a profit.
A major concern surrounding the annexation was Crimea's dependence on tourism as it's main source of income, as most tourists came from Ukraine. Now they simply halved the price of plane tickets from mainland Russia to Crimea to encourage Tourism.
I don't know if the results of the referendum were falsified, it would not surprise me as it's always been the case with elections over there. But all Crimeans, not only ethnic Russians would greatly benefit from a change in government for the reasons mentioned above and they know it. My relatives told me about huge lines of people waiting at 9 AM, soaking in the rain to vote for joining Russia, including Tatars and Ukrainians. They also told me of the unprecedented joy and general happiness on the streets after the result was made public and even more so when Crimea finally rejoined Russia.
I want to stress the fact that I am by no means a supporter of Russia, its government or Putin. I despise their corruption and violations of human rights. But what is happening in Crimea is very positive change for the people on that peninsula from what I can tell by reading the news and keeping in touch with my friends in relatives there that are directly impacted by the events.