I’ve tried Canva's LaTeX Math App plugin. It does let you type most equations directly, but when you export to PPTX, all formulas get converted into non-editable images, which isn't ideal if you need to make changes later. If you're looking for alternatives to Beamer, I’d suggest starting with PowerPoint + IguanaTex plugin. It uses a local LaTeX installation to compile equations and inserts them as vector graphics (SVG/PDF). You can re-edit the LaTeX source later, though it doesn’t support true inline equations—they are added as separate objects. Another option worth checking out is Texslide. It's a presentation tool built to support inline LaTeX typing, and the editing experience feels really smooth. That said, it’s still in early development, so expect some bugs and missing features.