As people have said, YMMV. However, you are asking about lifetime changes; cis men don't get to age twenty-five and suddenly stop masculinizing. They get more facial hair and body hair, their hairline continues to change if they begin to bald, they often bulk up, and their voices tend to acquire more depth and timbre as they age. I have a cis friend who is in his sixties, and his singing voice went from baritone to bass ten or fifteen years ago. (This knowledge certainly made me less paranoid about my own post-transition vocal changes.)
Many trans men do get the most dramatic changes in the first year or two and the less dramatic changes over the next few years after that. Obviously, we are changing from female features to male features, so that first year is going to be pretty intense! I went from tenor to baritone in my second year, though, not my first. I had regular microshifts--some actually noticeable to people who spoke to me regularly--for years after that. I think the last microshift was about two years ago, so maybe I am done with that. Maybe not.
My sideburns came in quickly that first year, but the beard took considerably longer. I think that the vast majority of the beard progress was completed by five years in. At the seven-year mark (yikes, has it been that long?), I still don't know how much chest, arm, and leg hair I'm going to get; I want more, but only time will tell.
I know one guy in my local community whose voice isn't masculine at all and who, well, still looks like a butch lesbian. I saw him go through the first year or so on T, and he hasn't further masculinized five years after that. It happens occasionally. Another friend is a little more androgynous than obviously male, but he is also unusually short, and his voice is rather ambiguous. Still, he is rarely misread these days, but he took longer to be consistently read as male. The vast majority of us who didn't "pass" before T seem to get enough results--maybe not as many as we'd like, but enough to "pass" consistently--within one to five years (some earlier). But that's just a ballpark figure based on my observations. And the little changes continue; we just don't notice them so much.
ETA: I started on the so-called full dose because I was already forty-six, and my endo recognized that I had been holding off for twenty years and wanted to get into it. If I'd asked for a lower dose, I'm sure he would have obliged. Many doctors refuse to go to the full dose all at once, and they are probably right.
I was on finasteride for a while (two stretches for about a year and a half total); there was some interference with my masculinization. And I've been on about 80% of the original dose for two or three years now (seven total, as I mention above).
