Compare tools not by 'whether they detect outages', but by how quickly they lead to a decision.
Ask yourself 3 questions:
1. How quickly do you detect the problem?
Time-to-detect
2. How quickly do you diagnose the cause?
Time-to-diagnose
3. How efficiently do you communicate status to customers?
Time-to-communicate
Consistent flow: detection -> diagnosis -> status communication -> report
RUM + synthetic + classic uptime in one place
Private agents for internal networks
Strong status pages layer for agency/client-facing communication
If you only need the cheapest 'ping every few minutes' and don't have critical services, a simpler tool might suffice.