I imagine it largely depends on your goals. I wanted to get insights into how my blood pressure is affected by various activities (e.g. when sleeping, traveling, working, meditating, working out, after physical/emotional stress, when taking certain medicines, etc.) I also wanted to see long-term trends month-over-month and year-over-year. For these purposes Aktiia was the easiest option I found.
As a side note, the accuracy of individual readings is not something I’m concerned about since they’d get averaged out over time. Even if a reading shows 120/80 while in reality it might be 125/85, my main focus is on trends and correlations.