The Snapdragon 765 is a pretty great chip, combining a selection of the high-end features of Qualcomm's 800 series with a lower price that puts it on the higher end of the mid-range category. According to an alleged leak on Telegram, the next upgrade to this class will be significant. The Snapdragon 775's biggest change is a shift to the smaller and more efficient 5 nanometer fabrication process, as seen on the 888.
The Telegram leaker "XiaomiUI" (not officially affiliated with Xiaomi) indicates that, Like the 765, the 775 system-on-a-chip would come in standard and 5G variants. The CPU design would jump from the Kryo 475 to a new design, labelled "Kryo 6xx" in the document, with a similar Adreno 6xx placeholder model for the GPU. RAM would be available in LPDDR5 3200mHz, a huge bump up, or LPDDR5 2400mHz, which is still a modest gain. The camera signal processor jumps from the Spectra 355 to 570, with a maximum capability of triple 28 megapixel sensors operating at once. Display supports 4K at 60 frames per second, or a more typical 1080p at up to 120fps.
Hardware comparison between the SM7250 (Snapdragon 765) and SM7350 (Snapdragon 775), upgrades in bold.
This unconfirmed hardware would make the 5nm Snapdragon 775 almost as powerful as the 7nm 870, and potentially better in some areas like memory speed and multi-camera performance. It wouldn't be able to go toe-to-toe with the 888, but then it wouldn't need to—it would be used in much cheaper devices. Considering that crucial details like the CPU and GPU model are missing, and assuming that it's a genuine leak, it might take quite a while for the SoC to show up in devices.