If you're a developer/coder/sysadmin you can find companies that will hire you speaking only English. This is very common, though much more so in Helsinki.
In everyday life speaking Finnish will be beneficial, for obvious reasons. I've been here a few years now, having moved from Scotland. Using English I've been able to get my brain scanned, buy a couple of flats, deal with daycare (I became a parent after moving here), and most bureaucracy.
Finnish is indeed hard to learn, but even getting the basics down will make your life easier and better.
Almost everyone in Finland speaks either good or fluent English. Movies and TV shows aren't dubbed apart from some animated content, usually for kids. Domestic media can only create so much content for a population of 5 million, so the population is constantly subjected to English language media.
There's also regions along the coast where a sizable portion, or even the majority of people, are Swedish speaking[1] (and bilingual to various degrees). Swedish is an official language, and if you want to be a pain in the ass to the 95% of the population that doesn't speak Swedish apart from the mandatory school courses, you are entitled by law to get service in Swedish.
Working only in English is obviously harder, but if you want to live here, don't let that stop you.
In everyday life speaking Finnish will be beneficial, for obvious reasons. I've been here a few years now, having moved from Scotland. Using English I've been able to get my brain scanned, buy a couple of flats, deal with daycare (I became a parent after moving here), and most bureaucracy.
Finnish is indeed hard to learn, but even getting the basics down will make your life easier and better.