Yesterday two directors bought shares after GSK settled the Californian court case, it looks like they are picking off individual cases . there must be some truth in the litigation or GSK would have let the case pan out in court.
Jonathan Symonds bought 6000 shares at 1440p cost £86387.40p
Julie Brown bought 22500 shares at 1429p cost £321554.25p

Probably because you shouldn't put all your eggs in one basket.
I hold GSK in my ISA for the dividend, like you point out, little growth of late.
Walmsley took control in April 2017 when the share price was hovering around £16/share and 80p dividend.
Since taking over she caved into Elliott Advisors demands and out popped Haleon..GSK were late to the party with their COVID vaccine and they were the specialist in that field of research.
Personally I think she is the wrong person for the job, until she goes it will stagnate, I should have invested my money into Astra Zeneca.

GSK, like so many other companies, is a bond proxy. As Dan says, you look back after ten years and see that neither your capital nor income has increased. Better to put it into a UK equity income trust (if you want to stay within the UK) or a global equity income trust like JGGI paying 4%.

Sold out of GSK having gone nowhere in the 9 years I held it. Hanging on to HALEON though........We will see.

Evidently GSK - like many of us - was sexy for a few short years back in the late '90's. I've held them for 15 years and they've always been stolid. Never thought of them as a bond proxy til Keith C put it in mind but it makes sense, I seldom think of them and then only as ballast in the portfolio.

The comparison that did occur to me is between GSK and a regular pension. I know caveats apply on the pensions side and they have been bound by regulation etc..Still, if a pension can't beat the GSK proposition I think its customers would be entitled to put some questions to the administrators. But I suppose most people of pensionable age don't yet think of their pensions as assets.