The enormous control the leadership class can exercise with social engineering these days, the power of present day information technology and the implements of mass persuasion, are too strong to entrust into the hands of fundamentalist rulers who would claim the rights of the clergy and wed them to the prerogatives of the state’s police power.
Should that clergy's hold be tempered by forcing it every seven years and twice every century to relinquish the centrality of its place in the national project, it wouldn't be such a scary prospect for the rest of the time.
That is possibly the reason why the yovel begins after Yom haKippurim. The timing denotes the onset of shemitta.
Shemitta represents the temporary suspension of clerical supremacy. The priests have just finished purifying the sanctuary, and now they can all also, as it were, go on sabbatical. No tithing during the sabbatical year. The entire nation resembles the priesthood in that no-one during the shnat sheviit has a direct claim on the land.