
For the Sprint Goal:
“The Sprint Goal is the single objective for the Sprint. Although the Sprint Goal is a commitment by the Developers, it provides flexibility in terms of the exact work needed to achieve it.” - Scrum Guide 2020
The Product Goal should be a commitment as well but Scrum struggles with this term a lot. More:
https://medium.com/serious-scrum/scrum-and-its-struggles-with-commitment-2a4eb7202ae2
An example:
https://www.scrum.org/resources/commitment-vs-forecast

The Product Goal is already a commitment and it is explicitly defined so in the Scrum Guide. The title of the section therefore reads: “Commitment: Product Goal”.
There are four explicitly defined commitments in Scrum:
Commitment in Scrum does not mean ‘doing what you are told to do’, it means to support each other as professionals, working through tough challenges.

Yes, Sjoerd, but it is the commitment for the Product Backlog. I’d like to make it clear - the Product Goal is a commitment by the Scrum Team. In my opinion, this is more than just wording.
It is not clear for many people. For example, Stephanie wrote about commitment (understood as a value) without mentioning the Product Goal at all: https://www.scrum.org/resources/blog/maximize-scrum-scrum-values-commitment-part-4-5

I misinterpreted it as well for this same reason.
Sprint Goal = Commitment for Sprint Backlog (which always belongs to a Scrum Team).
Product Goal = Commitment for Product Backlog for a specific Scrum Team. There can be multiple teams working on the same Product, and thus the same Product Backlog.

Good point. I think the Scrum Team should understand and interpret the current Sprint Goal in the context of the Product Goal.
A single Product Goal can support collaboration between different Scrum Teams working on the same product.

What kind of improvement would such an amendment bring?

I’m hesitant with this one. I agree that the product goal is already a commitment in SG 2020, and the fact that some practitioners may overlook it is not quite convincing. I am curious to see how this suggestion progresses further!

In the accountablity of a developer, it is the people doing the work. Only those people that are actively involved in contributing work can get the goal done.
Don’t confuse the difference between accountability versus job title.
A person with a job title of Scrum Master or Product Owner will have accountabilities, however if they engage and work in the team on items then they are also taking on the “developer accountablity”. Thus this is inclusive.
A job title SM or PO that does not do work, in the team cannot do anything besides micro-manage on crack the whip. The self-managing developers are the only ones that can ACTIVELY do something about it as they do the work needed to reach the sprint goal.
This is confusing Job title with accountability. In my view this is very clear.
Committing to something that is ephemeral is not feasible. The same reason why sprints exist is to lock in a goal and not alter it within a constrained amount of time.

@Ksenia Naumchik @Sjoerd Nijland
A nice confirmation that the Product Goal is a commitment for the Scrum Team, not only for the Product Backlog, Values section:
https://www.scrum.org/what-professional-scrum
I wonder if they will explicitly state it in the next version of the Scrum Guide, as I suggested ;)