Documents from/to any agency, including anything that has any tax relevance, - generally speaking (there are many caveats) - shall be signed with services compliant with the e-signature standards provided by Regulation 2014/910/EU (in short: PADES, CADES, XADES).
Out of curiosity: is there a similar requirement in terms of e-signature in the US when documents need to be sent to some agency, such as the IRS?
The purpose of someone like Docusign is to provide a trusted third party to provide evidence.
For most purposes GPG signed email (or anything else with a similar signature) would work perfectly well provided you could prove who the keys belong to. In fact it would be better than DOcusign who can (from the few documents I have signed) ultimately only really show they sent an email with a signing link to your email address.
The last one from them has a warning:
"Do Not Share This Email This e-mail contains a secure link to DocuSign. Please do not share this e-mail, link or access code with others."
Docusign always saves the IP addresses and timestamps for any signatures. In addition it can be set up to require 2FA prior to accepting a signature - eg our lawyers will set it up to require an SMS 2FA confirmation and I've heard them say that this is a hard requirement for deeds as opposed to simple contracts (tho whether that's down to law firm policy, Docusign policy or court precedent I don't know).