You should use the JD-GUI options to disable writing source lines as noted around 10:00

Also around that mark, commenting on the "human" like nature of the de-compilation, most Java decompilers are very accurate when fed non-obfuscated code. You can find an academic level comparison of their accuracy here: https://arxiv.org/abs/1908.06895

Around 28:00 regarding decompilation using language features matching the version of the bytecode, CFR has the most fine level of control for this.