You always make decisions with incomplete information. Even when you do a ton of research and comparison, you never have all the data.
People tend to overdo the research part when deciding for small stuff and neglect it when deciding big stuff.
Even more often, people take the opportunity to delay the decision by analyzing options.
In most cases, the more you delay, the more loss you incur on yourself. Most decisions are easily reversible or have low impact.
Changing your phone is not a major decision. Or going for a vacation.