Most people in this country support Conservative values and ideology for the most part.
Problem is that recent Conservative governments (since 2016 or so) have not been effective or competent in implementing Conservative values and ideology. Voters understood this even back in 2017 and wanted change.
Despite this, voters hated Jeremy Corbyn so much that they still chose to give the Conservatives another 2 election terms in power.
Of course, the ineffective Conservatives were emboldened by this, falsely assuming they were elected because of their success rather than dislike of the opposition, and so continued their ineffective/incompetent practices, frankly getting much worse over the Boris era. This ego is a common reason why incumbents lose support as their tenure extends.
Losing to the Conservatives in 2019 finally instigated the desired change in Labour, installing a more centrist leader in Keir Starmer who possessed more tolerable views for the core of voters.
As before, the Conservatives continued their ineffective/incompetent practices but the difference is that there is now an opposition that the core of voters can at least tolerate, in order to force the Conservative party to change for the better. As long as that remains true at the next general election, Labour will win.
Once Labour are in power, two things can happen. The first is that Keir ends up being catastrophically incompetent - i.e. Liz Truss level. If that's the case then Conservatives won't be motivated to change much and will easily get back into power at the next election. Disaster for democracy and the future of the country.
Alternatively, Keir could end up similar to or a little bit more/less effective than some recent Conservative governments. If that's the case (and it's the more likely scenario) then it's likely that the Conservatives will have to do a proper reorganisation and realign with what the core voters desire. If they do, and Labour get complacent like the Conservatives did these past few years, then the Conservatives will get back in. If Labour don't get complacent and evolve proactively, they can stay in power. Win-win for the people.
And thus parties evolve and change to better reflect the desires and aims of the population.
The very best thing for a successful democratic country is (a) the existence of palatable opposition parties, and (b) the willingness of citizens to vote for said palatable opposition parties if the incumbent becomes complacent.