A lot of companies are not allowed to accept bitcoins as a payment option, because Bitcoin is not defined as a currency in their country. I think it is difficult for their accountants to explain this to their auditors, when they get audited for taxes.
PayPal might also have signed some deal with Reddit and this could have influenced their decision to stop accepting bitcoins. We do not know what bribes are being paid, to influence decisions like this.
I know they used the "high fees" excuse, when Bitcoin struggled with scaling, but the new Lightning Network changed this, so they do not have an excuse anymore.