Online games often use much less bandwidth than video streaming. The experience depends more on latency, jitter and loss than on extremely high download speed.
Priorities
Aim for a stable connection, low latency to the game region, low jitter and minimal loss.
Uploads matter
Cloud backups or large uploads can create queueing and increase latency even when download bandwidth looks healthy.
Use the verdict carefully
The app's gaming verdict is a practical browser estimate, not a guarantee of performance to a specific game server.