[jamesu]

Generally you want to avoid wasting too much memory on a GPU, even today. That large text box texture also has to go over the PCI bus which can cause stalls depending on when its uploaded and if the GPU ends up having to evict resources. If you end up having a lot of independent texture text boxes being rendered by the comparatively slower CPU, that could add up quickly and cut into your budget.

Drawing using a glyph atlas is still a way better use of resources. Modern text rendering pipelines will also often use either SDF or encoded bezier curves to improve glyph legibility when scaling which is also a great way of saving more memory.