Which Cortex-A core is most suitable for UI + Cloud + Firmware Upgrade HD Video embedded Linux product?

Hi ARM Community,

We are developing a commercial embedded Linux product (HMI machine)
using a Cortex-A application processor with the following workload:

- Qt/QML based touch UI (animations, transitions)
- HD video playback (1080p)
- Cloud application (MQTT, TLS, OTA updates)
- Continuous background logging
- 24x7 operation

We are evaluating three options:
- Cortex-A17
- Cortex-A55
- Cortex-A72

Our concern is choosing a core that can reliably handle UI + cloud +
video simultaneously without UI lag or cloud instability.

From our initial analysis, Cortex-A72 appears more suitable due to
higher single-core performance and out-of-order execution, while
A55 seems optimized for efficiency and A17 is older architecture.

We would appreciate guidance from ARM experts on:
1. Which core is most suitable for this workload?
2. Is Cortex-A55 sufficient for such multitasking workloads?
3. Is Cortex-A17 still recommended for new designs?

Thanks in advance for your advice.