Certified GKH Gardening Expert
This is highly debated subject.
Ideally, you prune these off, because they make caring for the shrub extremely difficult later on. You want space near the ground to be open so that there can be airflow to avoid disease.
If you choose to keep them, tying them up may prevent them from gaining their own structural strength since something will be doing that for them. Sometimes, they do develop properly that way, but it leaves the branches open to sprouting at the base, which will further your pruning problem later on.
I know it is hard to prune off so much growth at once, but it will help the structure in the long run, but should you keep them, I would leave them alone completely until you see how they will contribute to the structure.
This article will give you information on their care: https://www.gardeningknowhow.com/ornamental/shrubs/photinia/rejuvenating-red-tip-photinia.htm