We have both, i went from the S7+ (now my wifes), to an S8 Ultra (now my sons), I moved to a Laptop the Book2Pro.
S8 Ultra is amazing, especially coupled with the matching keyboard case.
I would go with OneDrive as is has better Samsung integration, key one being Gallery sync, add O365 you will begin to ask why do I need a laptop/pc.
Regards Obsydian - (Car & Tech Evangelist)
MY DEVICES: ZFold4, Watch6 Classic, Book2 Pro i5 5G [Laptop], Buds Pro2, M70A 32 & 43”; [Monitor], Smart Tags, Dell Inspiron G5 [Laptop] / FAMILY DEVICES: ZFlip3, ZFlip4, ZFlip5, Watch6 Classic, S8 Ultra; S7+ [Tablet], Buds Pro, iPhone 12, iPad Air 2, Air tags, iPad Mini 5, iPad Pro 12.9 GEN2 [Tablets] / HOME DEVICES: QN95A [TV], Q900A / SWA900S [Soundbar, Rears], MC28M6075 and MC32K7055 [Microwave], Jet 75 Complete (Vacuum), Samsung Level [Speaker]