The duty and role of government is to act in the interests of those with power and influence. If a vote has more power and influence than money or connections due to how the government is structured or elected then the government can represent the interests of the people.
However, even voters are not equal in the US with those in Wyoming holding almost 3x the voting power for president compared to California due to the electoral college. Senate votes are an entirely different ballgame where small population states are equal to large states in theory but the vote count behind the senator may be millions vs tens of thousands. Also, the less populated but more numerous red states have led to a tyranny of the minority in the US Senate since 2010. If you are curious about that look at the number of justices Trump has appointed vs Obama, and Obama had 2 full terms: https://www.pewresearch.org/fact-tank/2020/07/15/how-trump-c...
The US is not really a functional democracy or represenatative republic at this point. Money and power run most policy: https://www.theatlantic.com/business/archive/2015/04/how-cor... (from 2015).
Lobbying dollars hugely outweigh voter preference in policy: https://www.americanprogress.org/issues/economy/reports/2014...
And if you are a company looking to make a profit lobbying may be the best investment to make over capital or other useful growth moves: https://medium.com/numbers-that-matter/return-on-investment-...
That's right, ROI on lobbying is about 200,000% though 10 years it ago it was closer to 20,000%: https://sunlightfoundation.com/2009/04/09/return-on-lobbying...
There's been an admin change in that time plus the Citizens United decision. Remember there are many questions around where PPP loans went, including millions to the newly appointed USPS leadership plus Senator Mitch McConnell (R-KY), Senate Majority leader, and his wife, Elaine Chao, Secretary of transportation: https://www.marketwatch.com/story/lawmakers-and-transportati...
Trump himself won with a 2.8 million popular vote deficit, similar to Bush in 2000. There are 3 other examples in the mid 1800's. In 2016 the GOP won a minority of votes in the US house yet held a 10% seat majority alongside a lopsided Senate. These are not symbols of a functional republic or election process, or at lest one that reflects the will of the people. From the 2016 election results alone your first statement on the duty and role of government is failed by the US. We are at risk of becoming a failed democracy for similar reasons.
Lobbying and campaign finance operations are destroying the value of voter preference and need to be reigned in through massive overhaul of the campaign and election processes. I'm all for setting a window for campaigning like the UK, assigning a budget from public money that ALL donations go into to remove lobbying issues, as well as an overhaul of the actual voting mechanisms reverting to paper ballots handled entirely by mail and air gapped technology using a ranked choice or first alternative process to determine the popular vote like Maine implemented this year. Connect that to the bill going around for states to pass their electors to the popular vote winner directly and you have the start of a government serving at the will of the people, not lobbyists, a minority, the powerful.